What does mlc. Compare the type of memory MLC and TLC in SSD drives

Greetings dear friends! When choosing an SSD drive for a computer (you can learn more about this), you will find various types of memory in the characteristics. There are not so many of them, but they still differ in parameters.

Today we’ll talk about what type of memory is best for an SSD and what you should pay attention to first. Shall we start?

Existing Options

Almost every solid state drive today runs on NAND memory. Depending on the features, they are divided into three types:

• SLC - single-level. Each cell remembers one bit depending on the state - it can be turned on or off. It has the lowest power consumption, the highest rewriting speed and the number of its cycles. However, it is expensive, so it is used mainly in cool server solutions.
• MLC - multi-level. The cell remembers two bits. It costs less, as the characteristics are "simpler". Used primarily on workstations and mid-range servers.
• TLC - three-level. The cell remembers three bits. It has the highest density, is less hardy and works relatively slower. The most affordable type, therefore, it is widely used in solid-state drives designed for mass consumption.

These types are of the planar type, meaning they are "flat". Their common drawback is that in order to increase the density, it is necessary to reduce the technical process, and it is impossible to do this indefinitely for physical reasons.

3D cells are free of these shortcomings. Cylinder shaped. They are called 3D V-NAND or 3D TLC. Specifications correspond to the planar type of TLC memory.

Manufacturers

There are fewer companies that make chips for solid state drives than there are brands that make SSD drives.
In 2017, production was carried out by:

• Intel/Micron;
• Toshiba/SanDisk
• Hynix;
• Samsung.

It is no coincidence that the first two paragraphs contain two companies through a slash - these brands have established joint production and label products in approximately equal proportions.

All brands that produce SSDs buy chips from these companies, so essentially the same storage devices are installed on different brands. There are no fundamental differences between memory brands: they are produced according to a single technological process and cost approximately the same.

The price is already affected by transportation costs: in 2018, buying a drive with memory made in Singapore will cost less than with memory made in the USA, given that the cost of chips and controllers is also approximately the same.

Which one to prefer

Having studied any performance table, it is easy to make a choice:

• TLC or MLC - the latter is more reliable and faster;
• MLC or 3D NAND - the latter is slower and designed for fewer rewrite cycles;
• TLC or MLC 3D V-NAND - as mentioned above, single-level memory is better in terms of technical parameters.

Since solid state drives are bought primarily for the sake of increasing computer performance, faster loading of the operating system and games, it is logical that it is preferable to use single-level memory. However, everything depends on the price: as I noted, such a pleasure will be very expensive.
Is it rational to overpay if you upgrade or collect, albeit fancy, but still an ordinary home computer? Definitely not.

Therefore, TLC is exactly the kind of cells that you should focus on when choosing a solid state drive. By the way, in this case, the publication "" will be useful to you. Although this memory is slow compared to other types, it is significantly faster than a conventional hard drive.

About hard drive manufacturers and which brand to prefer, you can.

And as a possible purchase, I can recommend the device Kingston SSDNow A400 240GB 2.5″ SATAIII TLC (SA400S37/240G), which has very good parameters at an affordable price, and you can buy it in this popular online store.

Thank you for your attention and see you in the next posts. Share this article with your friends on social networks and don't forget to subscribe to the newsletter!

First SSD, or solid state drives using flash memory, appeared in 1995, and were used exclusively in the military and aerospace fields. The huge cost at that time was compensated by the unique characteristics that allow the operation of such disks in aggressive environments over a wide temperature range.

In the mass market, drives SSD appeared not so long ago, but quickly became popular, as they are a modern alternative to a standard hard drive ( HDD ). Let's figure out what parameters you need to choose a solid state drive, and what it is all about.

Device

Out of habit SSD is called a "disk", but it could rather be called " solid box”, since there are no moving parts in it, and nothing similar in shape to a disk either. The memory in it is based on the physical properties of the conductivity of semiconductors, so that SSD- a semiconductor (or solid state) device, while a conventional hard disk can be called an electro-mechanical device.

Abbreviation SSD just means " solid state drive ", that is, literally, " solid state drive". It consists of a controller and memory chips.

Controller- the most important part of the device that connects the memory with the computer. Main characteristics SSD- the data exchange rate, power consumption, etc., depend on it. The controller has its own microprocessor running according to a pre-installed program and can perform the functions of correcting code errors, preventing wear, and cleaning debris.

Memory in drives can be either non-volatile ( NAND), and energy-dependent ( RAM).

NAND memory won at first HDD only in the speed of access to arbitrary memory blocks, and only since 2012, the read / write speed has also increased many times over. Now in the mass market drives SSD are represented by models with non-volatile NAND-memory.

RAM The memory is characterized by ultra-fast read and write speeds, and is built on the principles of computer RAM. Such memory is volatile - in the absence of power, the data disappears. It is usually used in specific areas, such as speeding up work with databases, it is difficult to find it on sale.

Differences between SSD and HDD

SSD distinguishes from HDD First of all, the physical device. Thanks to this, it boasts some advantages, but it also has a number of serious disadvantages.

Main advantages:

· Speed. Even from the technical specifications, it can be seen that the read / write speed of SSD several times higher, but in practice the performance can vary by 50-100 times.
· No moving parts and therefore no noise. It also means high mechanical resistance.
· The speed of random access to memory is much higher. As a result, the speed of work does not depend on the location of the files and their fragmentation.
· Much less vulnerable to electromagnetic fields.
· Small size and weight, low power consumption.

Flaws:

· Resource limitation by rewriting cycles. It means that you can overwrite a single cell a certain number of times - on average, this figure varies from 1,000 to 100,000 times.
The cost of a gigabyte of volume is still quite high, and exceeds the cost of a regular HDD several times. However, this shortcoming will disappear with time.
Difficulty or even impossibility of recovering deleted or lost data associated with the hardware command used by the drive TRIM, and with high sensitivity to power supply voltage drops: with such damage to memory chips, information from them is irretrievably lost.

In general, solid state drives have a number of advantages that standard hard drives do not have - in cases where speed, access speed, size and resistance to mechanical stress play a major role, SDD pushes hard HDD.

How much SSD will you need?

The first thing you should pay attention to when choosing SSD- its volume. On sale there are models with a capacity of 32 to 2000 GB.

The solution depends on the use case - you can install only the operating system on the drive, and limit yourself to the volume SSD in 60-128 GB, which will be sufficient for Windows and installation of basic programs.

The second option is to use SSD as the main media library, but then you need a disk with a capacity of 500-1000 GB which will be quite expensive. This only makes sense if you're working with a lot of files that need to be accessed really quickly. With regard to the average user - not a very rational price / speed ratio.

But there is another property of solid-state drives - depending on the volume, the write speed can vary greatly. The larger the disk capacity, the higher the write speed, as a rule. This is due to the fact that SSD is able to use several memory crystals in parallel at once, and the number of crystals grows along with the volume. That is, in the same models SSD with different capacities of 128 and 480 GB, the difference in speed can vary by about 3 times.

Given this feature, we can say that now the most optimal choice in terms of price / speed can be called 120-240 GB SSD models, they will be enough to install the system and the most important software, and maybe for several games.

Interface and form factor

2.5" SSD

The most common form factor SSD is a 2.5 inch format. It is a “bar” with dimensions of approximately 100x70x7mm, they may vary slightly from different manufacturers (± 1mm). The interface of 2.5" drives is usually SATA3(6 Gbps).

Advantages of the 2.5" format:

• Prevalence in the market, any volume is available
• Convenient and easy to use, compatible with any motherboard
• Democratic price

Disadvantages of the format:

• Relatively low speed among ssds - up to a maximum of 600 Mb / s per channel, against, for example, 1 Gb / s for a PCIe interface
• AHCI controllers that were designed for classic hard drives

If you need a drive that is convenient and easy to mount in a PC case, and your motherboard has only connectors SATA2 or SATA3, then 2.5" SSD drive- This is your choice. The system and office programs will obviously boot faster compared to the HDD, and the average user will not notice a big difference with faster solutions.

mSATA SSD

There is a more compact form factor - mSATA, sizes 30x51x4 mm. It makes sense to use it in laptops and any other compact devices where the installation of a conventional 2.5” drive is impractical. If they have a connector of course mSATA. In terms of speed, it's still the same specification. SATA3(6 Gbps), and does not differ from 2.5".

M.2 SSD

There is another, the most compact form factor M.2, gradually changing mSATA. Designed mainly for laptops. Dimensions - 3.5x22x42 (60.80) mm. There are three different bar lengths - 42, 60 and 80mm, pay attention to compatibility when installing in your system. Modern motherboards offer at least one U.2 M.2 slot.

M.2 can be either SATA or PCIe. The difference between these interface options is in speed, and quite a big one at that - SATA drives can boast an average speed of 550 Mb / s, while PCIe, depending on the generation, can offer 500 Mb / s per lane for PCI-E 2.0. and speeds up to 985 Mb/s per PCI-E 3.0 lane. Thus, an SSD installed in a PCIe x4 slot (with four lanes) can exchange data at speeds up to 2 Gb / s in the case of PCI Express 2.0 and up to almost 4 Gb / s when using PCI Express third generation.

At the same time, the differences in price are significant, an M.2 form factor drive with a PCIe interface will cost, on average, twice as much as a SATA interface with the same volume.

The form factor has a U.2 connector, which may have connectors that differ from each other keys- special "cutouts" in them. There are keys B and , and also B&M. Different bus speeds PCIe: key M provide speed up to PCIe x4, key M speed up to PCIe x2, like the combined key B&M.

B- the connector is not compatible with M- connector, M-connector, respectively, with B- connector, and B&M connector is compatible with any. Be careful when purchasing M.2, since the motherboard, laptop or tablet must have a suitable connector.

PCI-e SSD

Finally, the last existing form factor - as an expansion board PCI-E. Mounted, respectively, in the slot PCI-E, have the highest speed, of the order 2000 MB/s read and 1000 MB/s write. Such speeds will cost you very dearly: it is obvious that choosing such a drive is worth it for professional tasks.

NVM Express

There are also SSD, having a new logical interface NVM Express, designed specifically for solid state drives. It differs from the old AHCI by even lower access latencies and high parallelism of memory chips due to a new set of hardware algorithms.
There are models on the market both with a connector M.2, as well as in PCIe. The downside of PCIe here is that it will take up an important slot, which can be useful for another board.

Since the standard NVMe designed specifically for flash memory, it takes into account its features, while AHCI Still, it's just a compromise. So, NVMe is the future of SSDs and will only get better over time.

What type of memory is best in an SSD?

Understanding the types of memory SSD. This is one of the main characteristics SSD, determining cell rewriting resource and speed.

MLC (Multi Level Cell)- the most popular type of memory. Cells contain 2 bits, unlike the 1st bit in the old type SLC which is almost out of stock. This results in a larger volume, which means a lower cost. Recording resource from 2000 to 5000 rewriting cycles. In this case, "overwriting" means overwriting each cell of the disk. Therefore, for a 240 GB model, for example, you can record at least 480 TB of information. So, such a resource SSD even with constant intensive use, 5-10 years of commercials should be enough (for which it will still be very outdated). And for home use, it will last for 20 years at all, so the limited rewriting cycles can be completely ignored. MLC- this is the best combination of reliability / price.

TLC (Triple Level Cell)- it follows from the name that 3 bits of data are stored in one cell at once. The recording density here is compared to MLC higher by whole 50% , which means that the rewriting resource is less - only from 1000 cycles. Access speed is also lower due to higher density. The price is not much different now. MLC. It has long been widely used in flash drives. The service life is also sufficient for a home solution, but the susceptibility to uncorrectable errors and the "death" of memory cells is noticeably higher, and during the entire service life.

3D NAND- it is more a form of memory organization, and not its new type. Exists like MLC, and TLC 3D NAND. Such a memory has vertically placed memory cells, and a separate memory chip in it has several levels of cells. It turns out that the cell has a third spatial coordinate, hence the prefix "3D" in the name of the memory - 3D NAND. It features a very low error rate and high endurance due to the larger process technology of 30-40nM.
The manufacturer's warranty for some models reaches 10 years of use, but the cost is high. The most reliable type of memory in existence.

Differences between cheap SSDs and expensive ones

Disks of the same volume can differ greatly in price even from the same manufacturer. A cheap SSD can differ from an expensive one in the following ways:

· Cheaper type of memory. In ascending order of cost / reliability, conditionally: TLC≥ MLC ≥ 3D NAND.
· Cheaper controller. Also affects read/write speed.
· Clipboard. The cheapest SSDs may not have a clipboard at all, this does not make them much cheaper, but it significantly reduces performance.
· Protection systems. For example, expensive models have power interruption protection in the form of reserve capacitors, which allow you to correctly complete the write operation and not lose data.
· Brand. Of course, a more popular brand will be more expensive, which does not always mean technical superiority.

Conclusion. What is more profitable to buy?

It is safe to say that modern SSD drives are quite reliable. The fear of data loss and the negative attitude towards solid state drives as a class are completely unjustified at the moment. If we talk about more or less popular brands, then even a cheap TLC memory is suitable for budget home use, and its resource will last you for several years at least. Many manufacturers also offer a 3-year warranty.

So, if you are limited in funds, then your choice is a capacity of 60-128 GB to install the system and frequently used applications. The type of memory is not so critical for home use - TLC it will be or MLC, the disk will become obsolete before the resource is exhausted. Other things being equal, of course, it is worth choosing MLC.

If you are ready to look into the middle price segment and value reliability, then it is better to consider MLC SSD 200-500 GB. For older models, you will have to pay about 12 thousand rubles. At the same time, the volume will be enough for you for almost everything that should work quickly on a home PC. You can also take models of even more increased reliability with memory crystals 3D NAND .

If your fear of flash memory wear and tear reaches panic levels, then it's worth looking at new (and expensive) technologies in the form of storage formats. 3D NAND. And if no jokes, then this is the future SSD– high speed and high reliability are combined here. Such a drive is suitable even for important server databases, since the write resource here reaches petabyte, and the number of errors is minimal.

In a separate group, I would like to allocate drives with an interface PCI-E. It has high read and write speed 1000-2000 Mbps), and on average more expensive than other categories. If speed is the top priority, then this is the best choice. The disadvantage is that it occupies a universal PCIe slot; motherboards of compact formats can have only one PCIe slot.

Out of competition - SSD with NVMe logical interface, the reading speed of which exceeds 2000 Mb / s. Compared to SSD compromise logic AHCI, has much greater queue depth and concurrency. High cost on the market, and the best performance - the choice of enthusiasts or professionals.

MLC or TLC - which is better to choose for your computer? All users who have ever used a solid state drive (SSD memory) speak positively about it. Thanks to him, your favorite applications load faster, and the overall efficiency of the system increases. In addition, these drives are much more durable and durable than traditional hard drives. But why are some types of memory more expensive than others? To answer this question, you need to understand the internal structure of drives of this type.

The SSD board can be divided into 3 main blocks:

1. 3D NAND memory (not to be confused with NOR Flash). This part is used to store data in non-volatile units that do not require constant power from the mains.
2. DDR. A small amount of volatile memory that needs power to store data. Used to cache information for future access. This option is not available on all drives.
3. Controller. Acts as an intermediary, connecting 3D NAND memory and a computer. The controller also contains firmware that helps manage the SSD.

NAND memory, unlike NOR, is built from many cells containing bits that are turned on or off by electrical charge. The organization of these switchable cells represents the data stored on the SSD. The number of bits in these cells is also determined by the type of memory. For example, in a Single Level Cell (SLC), a cell contains 1 bit. NOR drives are commonly used in network devices.

The reason the SLC stick has a small amount of memory is because of its small physical size compared to other Printed Circuit Board (PCB) components. Do not forget that the PCB includes a controller, DDR memory and 3D NAND memory, which must somehow be placed inside the PC system unit. MLC NAND memory doubles the number of bits per cell, while TLC triples. This has a positive effect on the amount of memory. NOR drives provide access to random information, which is why they are not used like a hard drive.

There are certain reasons why manufacturers continue to release flash memory with 1 bit per cell. SLC drives are considered the fastest and most reliable, but they are relatively expensive and have limited storage capacity. That is why such a device is most preferred for computers that are subjected to heavy loads.

What is SLC

In the confrontation between SLC vs MLC or TLC 3D, the first type of memory always wins, but it also costs much more. It also has more memory, but is slower and more prone to breakage. MLC and TLC are memory types that are recommended for normal day-to-day computer use. NOR is commonly used in mobile phones and tablets. Understanding your own needs will help the user choose the most suitable of all SSD drives.

The Single Level Cell gets its name from a single bit that turns on or off depending on the power supply. The advantage of SLC is that it is the most accurate when reading and writing data, and its continuous operation cycle can be longer. The number of allowed overwrites is 90000-100000.

This type of memory has taken root well in the market due to its high lifespan, accuracy and overall performance. Such a drive is rarely installed in home computers due to the high cost and small amount of memory. It is more suitable for industrial use and heavy loads associated with continuous reading and writing information.

Advantages of SLC:

• long life and more charge cycles than any other type of flash memory;
• fewer read and write errors;
• can operate over a wider temperature range.

SLC Disadvantages:

• high price compared to other SSDs;
• relatively small amount of memory.

Memory type eMLC

eMLC is flash memory optimized for the enterprise sector. It boasts improved performance and durability. The number of rewrites varies from 20,000 to 30,000. eMLC can be seen as a cheaper alternative to SLC, which borrows some of the advantages from its competitor.

eMLC Advantages:

• much cheaper than SLC;
• higher performance and endurance than conventional MLC NAND.

eMLC Disadvantages:

• loses to SLC in terms of performance;
• not suitable for home use.

MLC Flash Memory for Solid State Drive

Multi Level Cell memory gets its name from its ability to store 2 bits of data in one cell. The big advantage is the lower price compared to SLC. Lower cost, as a rule, becomes the key to the popularity of the product. The problem is that the number of possible overwrites of one cell is much less compared to SLC.

Advantages of MLC NAND:

relatively low price, designed for the mass consumer;
greater reliability compared to TLC.

Disadvantages of MLC NAND:

• less reliable and durable than SLC or eMLC;
• not suitable for commercial use.

TLC memory

Triple Level Cell is the cheapest form of flash memory. Its biggest drawback is that it is only suitable for home use and is contraindicated for use in business or industrial activities. The life cycle of a cell is 3000-5000 overwrites.

Advantages of TLC 3D:

• the cheapest SSD available on the market;
• able to meet the needs of most users.

Disadvantages of TLC 3D:

• the shortest life expectancy compared to other types;
• not suitable for commercial use.

SSD longevity

Like all good things in this world, an SSD cannot last forever. As noted above, the life cycle of a solid state drive directly depends on what kind of 3D NAND memory it uses. Many users are concerned about how long cheaper types of drives can last. Compared to MLC and TLC, SLC memory is more durable but costs more. Independent teams of enthusiasts tested affordable consumer-grade SSDs, most of which were MLCs, with only 1 using 3D NAND TLC. The results were promising. Before failure, most of these devices managed to pass 700 TB of information through themselves, and 2 of them - even 1 PB. This is truly a huge amount of data.

You can safely brush aside any fears that the SSD will fail in a short time. If you use MLC or TLC 3D V-NAND for everyday use such as storing music, photos, software, personal documents, and video games, you can be sure that the memory will last for several years. At home, it is impossible to load the computer the way they do with corporate servers. For those concerned about the lifespan of their memory, features like Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.) can help you keep track of the health of your SSD.

Choosing the Right SSD

In fact, the difference between commercial and consumer drives is so huge that it's hard to comprehend. Development teams have begun making expensive SSDs to meet the higher demands of high-tech activities, science and military developments that require constant processing of information.

Servers in large enterprises are a good example of using expensive flash drives because they run 24 hours a day, 5-7 days a week. That's why they need long, fast read/write times and increased reliability. Consumer drives are stripped down versions of commercial drives. They lack certain features but offer more storage. In addition, there is a pleasant trend in the world towards an increase in the performance of low-cost NANDs and a decrease in their cost.

What type of storage should you choose? SLC or MLC and TLC? We can conclude that SLC or eMLC memory is simply not needed for normal everyday use, so there is no point in spending a round sum of money on it. If you choose the type of NAND memory from TLC or MLC, then everything will depend on your financial capabilities.

TLC NAND is the most budgetary memory that can satisfy the needs of most consumers. MLC memory can be considered as a more advanced version of NAND memory for people who are ready to invest heavily in their personal computer. It is also suitable for those who plan to store their data for many years. If the message “NAND Flash was not detected” appeared on the monitor, then the memory has most likely exhausted its resource and failed.

IntroductionSolid-state drives or SSD (solid-state drive), that is, those based not on magnetic platters, but on flash memory, have become one of the most impressive computer technologies of the last decade. Compared to classic hard drives, they offer noticeably higher data transfer rates and orders of magnitude lower response times, and therefore their use raises the responsiveness of the disk subsystem to a whole new level. As a result, a computer that uses a solid state drive offers the user a truly rapid response to common actions such as loading the operating system, launching applications and games, or opening files. And this means that there is no reason to ignore progress and not use an SSD when building new or upgrading old personal computers.

The emergence of such a breakthrough technology was appreciated by many users. Demand for consumer-grade SSDs has skyrocketed, with more and more companies joining the SSD industry, trying to snatch their share of a growing and promising market. On the one hand, this is good - high competition gives rise to the establishment of favorable prices for consumers. But on the other hand, there is a mess and confusion in the market for client SSDs. Dozens of manufacturers offer hundreds of SSDs with different characteristics, and it becomes very difficult to find a suitable solution for each specific case in such a variety, especially without a thorough knowledge of all the subtleties. In this article, we will try to highlight the main issues related to the choice of solid state drives, and give our recommendations that will allow you to make a more or less informed choice when buying an SSD and get at your disposal a product that will be quite a worthy option in terms of price and consumer qualities.

The selection algorithm we preach is not too difficult to understand. We suggest not to get hung up on the features of hardware platforms and controllers used in various SSD models. Moreover, their number has long gone beyond reasonable limits, and the difference in their consumer properties can often be traced only by specialists. Instead, it is preferable to build a choice based on really important factors - the interface used, the type of flash memory installed in a particular drive, and which company produced the final product. It makes sense to talk about controllers only in some cases, when it really matters, and we will describe such cases separately.

Form factors and interfaces

The first and most noticeable difference between solid state drives available on the market is that they can have different external designs and be connected to the system via different interfaces that use fundamentally different protocols for data transfer.

The most common SSDs have an interface SATA. This is exactly the same interface that is used in classic mechanical hard drives. This is why most SATA SSDs look similar to mobile HDDs: they are packaged in 2.5-inch cases with a height of 7 or 9 mm. Such an SSD can be installed in a laptop in place of an old 2.5-inch hard drive, or you can use it in a desktop computer instead of (or next to) a 3.5-inch HDD without any problems.

Solid state drives using the SATA interface have become a kind of successor to the HDD, and this leads to their ubiquity and the widest compatibility with existing platforms. However, the modern version of the SATA interface is designed for a maximum data transfer rate of only 6 Gb / s, which seems prohibitive for mechanical hard drives, but not for SSDs. Therefore, the performance of the most powerful SATA SSD models is determined not so much by their capabilities as by the interface bandwidth. This does not particularly prevent mass solid state drives from revealing their high speed, but the most productive SSD models for enthusiasts try to bypass the SATA interface. However, it is SATA SSD that is the most suitable option for a modern common system.

The SATA interface is also widely used in SSDs designed for compact mobile systems. They impose additional restrictions on the size of components, so drives for such applications can be produced in a specialized form factor mSATA. Solid state drives of this format are a small daughter card with soldered chips and are installed in special slots found in some laptops and nettops. The advantage of mSATA SSD lies solely in its miniature size, mSATA has no other advantages - these are exactly the same SATA SSDs that are available in 2.5-inch cases, but in a more compact design. Therefore, such drives should be purchased only for upgrading systems that have mSATA connectors.

In the same cases, when the bandwidth offered by the SATA interface seems to be insufficient, you can pay attention to solid state drives with an interface PCI Express. Depending on which version of the protocol and how many lines are used by the drive for data transfer, the throughput of this interface can reach values ​​that are five times greater than the capabilities of SATA. Such drives usually use the most productive filling, and they significantly outperform the more familiar SATA solutions in terms of speed. True, PCIe SSDs are significantly more expensive, so they often fall into the most high-performance systems of the highest price category. And since PCIe SSDs are usually available as add-on cards installed in PCI Express slots, they are only suitable for full-sized desktop systems.

It should be noted that in recent years, drives with a PCI Express interface have become popular, operating under the protocol NVMe. This is a new software protocol for working with storage devices, which additionally increases system performance when interacting with a high-speed disk subsystem. Due to the optimizations made in it, this protocol really has the best efficiency, but today NVMe solutions need to be treated with caution: they are compatible only with the latest platforms and work only in new versions of operating systems.

While the bandwidth of the SATA interface is becoming insufficient for high-speed SSD models, and PCIe drives are bulky and require a separate full-size slot for their installation, drives made in the form factor M.2. It seems that M.2 SSDs have a chance to become the next standard, and they will be no less popular than SATA SSDs. However, you need to keep in mind that M.2 is not another new interface, but only a specification for the standard size of cards and the layout of the connector required for them. M.2 SSDs work on quite familiar SATA or PCI Express interfaces: depending on the specific implementation of the drive, either one or the other option is allowed.

M.2 cards are small daughterboards with components soldered onto them. The M.2 slots they require can be found on most modern motherboards today, as well as in many new laptops. Given that M.2 SSDs can also work through the PCI Express interface, it is precisely these M.2 drives that are most interesting from a practical point of view. However, at the moment the range of such models is not too large. Nevertheless, if we are talking about assembling or upgrading a modern high-performance system, in particular, a gaming desktop or laptop, we advise you to pay attention primarily to M.2 SSD models with a PCI Express interface.

By the way, if your desktop system is not equipped with an M.2 connector, but you still want to install such a drive, you can always do this using an adapter board. Such solutions are produced both by motherboard manufacturers and numerous small manufacturers of any peripherals.

Flash Memory Types and Drive Reliability

The second important question, which in any case will have to be dealt with when choosing, concerns the types of flash memory that can be found in current models of solid state drives. It is flash memory that determines the main consumer characteristics of SSDs: their performance, reliability and price.

Until very recently, the difference between different types of flash memory was only how many bits of data are stored in each NAND cell, and this divided the memory into three varieties: SLC, MLC and TLC. However, now manufacturers are adopting new approaches to cell layout and reliability in their semiconductor technologies, and the situation has become much more complicated. However, we will list the main flash memory options that can be found in today's solid state drives for ordinary users.

Should start with SLC NAND. This is the oldest and simplest type of memory. It involves the storage of one bit of data in each cell of the flash memory and due to this it has high speed characteristics and an exorbitant rewriting resource. The only problem is that storing one bit of information in each cell actively consumes the transistor budget, and this type of flash memory is very expensive. Therefore, SSDs based on such memory have not been produced for a long time, and they simply do not exist on the market.

A reasonable alternative to SLC memory with a higher storage density in semiconductor NAND chips and a lower price is MLC NAND. In such a memory, each cell already stores two bits of information. The speed of the logical structure of MLC-memory remains at a fairly good level, but endurance is reduced to about three thousand rewrite cycles. Nevertheless, MLC NAND is used today in the vast majority of high-performance solid-state drives, and its level of reliability is quite sufficient for SSD manufacturers not only to give their products a five-year or even ten-year warranty, but also promise the ability to overwrite the full capacity of the drive several hundred times. .

For the same applications where the intensity of write operations is very high, for example, for servers, SSD manufacturers assemble solutions based on a special eMLC NAND. In terms of operating principles, this is a complete analog of MLC NAND, but with increased resistance to constant overwriting. This memory is made from the finest, finest semiconductor crystals and can easily carry about three times the load than ordinary MLC memory.

At the same time, the desire to reduce prices for their mass products is forcing manufacturers to switch to cheaper memory compared to MLC NAND. In budget drives of the latest generations, it is often found TLC NAND- flash memory, each cell of which stores three bits of data. This memory is about one and a half times slower than MLC NAND, and its endurance is such that it is possible to overwrite information in it before the degradation of the semiconductor structure about a thousand times.

Nevertheless, even such a flimsy TLC NAND can be found quite often in today's drives. The number of SSD models based on it has already exceeded a dozen. The secret to the viability of such solutions lies in the fact that manufacturers add a small internal cache based on high-speed and highly reliable SLC NAND to them. In this way, both problems are solved at once - both with performance and with reliability. As a result, TLC NAND-based SSDs get speeds sufficient to saturate the SATA interface, and their endurance allows manufacturers to give end products a three-year warranty.

In the pursuit of cost reduction, manufacturers are looking to compress data within flash memory cells. This was the reason for the transition to MLC NAND and the spread of TLC memory drives that has now begun. Following this trend, we could soon encounter a QLC NAND-based SSD, in which each cell stores four bits of data, but what would be the reliability and speed of such a solution, one can only guess. Fortunately, the industry has found another way to increase the density of data storage in semiconductor chips, namely, their transfer to a three-dimensional layout.

Whereas in classical NAND memory, the cells are arranged exclusively planar, that is, in the form of a flat array, in 3D NAND the third dimension is introduced in the semiconductor structure, and the cells are located not only along the X and Y axes, but also in several tiers one above the other. This approach allows solving the main problem - the density of information storage in such a structure can be increased not by increasing the load on existing cells or by miniaturizing them, but by simply adding additional layers. In 3D NAND, the issue of endurance of flash memory is also successfully solved. The three-dimensional layout allows the use of production technologies with increased standards, which, on the one hand, provide a more stable semiconductor structure, and, on the other hand, eliminate the mutual influence of cells on each other. As a result, the resource of three-dimensional memory compared to planar can be improved by about an order of magnitude.

In other words, the three-dimensional structure of 3D NAND is ready to make a real revolution. The only problem is that it is somewhat more difficult to manufacture such memory than usual, so the start of its production was significantly extended in time. As a result, at the moment, only Samsung can boast of an established mass production of 3D NAND. The rest of the NAND manufacturers are just preparing to launch mass production of three-dimensional memory and will be able to offer commercial solutions only next year.

Speaking of Samsung's 3D memory, it currently uses a 32-layer design and is marketed under its own marketing name, V-NAND. According to the type of organization of cells in such a memory, it is divided into MLC V-NAND and TLC V-NAND- both are three-dimensional 3D NAND, but in the first case, each individual cell stores two bits of data, and in the second - three. Although the principle of operation in both cases is similar to conventional MLC and TLC NAND, due to the use of mature technical processes, its endurance is higher, which means that SSDs based on MLC V-NAND and TLC V-NAND are somewhat better in reliability than SSDs based on conventional MLC and TLC NAND.

However, speaking about the reliability of solid-state drives, it must be borne in mind that it depends only indirectly on the resource of the flash memory used in them. As practice shows, modern consumer SSDs, assembled on high-quality NAND memory of any type, are in reality capable of transferring the recording of hundreds of terabytes of information. And this more than covers the needs of most personal computer users. The failure of the drive when it runs out of memory resource is rather an out of the ordinary event, which can only be due to the fact that the SSD is used under too intense load, for which it was not actually intended initially. In most cases, SSD failures occur for completely different reasons, such as power outages or errors in their firmware.

Therefore, along with the type of flash memory, it is very important to pay attention to which company manufactured a particular drive. The largest manufacturers have more powerful engineering resources at their disposal and take better care of their reputation than small firms that are forced to compete with the giants primarily using the price argument. As a result, SSDs from large manufacturers are generally more reliable: they use known quality components, and thorough debugging of the firmware is one of the highest priorities. This is also confirmed by practice. The frequency of warranty claims (according to publicly available statistics from one of the European distributors) is lower for those SSDs that are manufactured by larger companies, which we will discuss in more detail in the next section.

SSD Manufacturers to Know About

The consumer SSD market is very young and hasn't consolidated yet. Therefore, the number of manufacturers of solid-state drives is very large - at least there are at least a hundred of them. But most of them are small companies that do not have their own engineering teams or semiconductor production, and in fact are engaged only in assembling their solutions from off-the-shelf components purchased from outside and their marketing support. Naturally, SSDs produced by such “assemblers” are inferior to products from real manufacturers who invest huge amounts of money in development and production. That is why, with a rational approach to choosing solid-state drives, you should pay attention only to solutions produced by market leaders.

Among these "pillars" on which the entire solid-state drive market rests, only a few names can be named. And first of all it is Samsung, which currently owns a very impressive 44 percent market share. In other words, almost every second SSD sold is made by Samsung. And these successes are not accidental. The company not only makes flash memory for its SSDs on its own, but also does without any third-party participation in design and production. Its SSDs use hardware platforms designed from start to finish by in-house engineers and manufactured in-house. As a result, advanced Samsung drives often differ from competing products in their technological advancement - they can be found in such progressive solutions that appear much later in products from other companies. For example, drives based on 3D NAND are currently only available from Samsung. And that is why the SSD of this company should be paid attention to by enthusiasts who are impressed by the technical novelty and high performance.

Second largest manufacturer of consumer-grade SSDs - Kingston with approximately 10% market share. Unlike Samsung, this company is not engaged in the independent release of flash memory and does not develop controllers, but relies on the proposals of third-party NAND memory manufacturers and the solutions of independent engineering teams. However, this is what allows Kingston to compete with giants like Samsung: skillfully choosing partners in each case, Kingston offers a very versatile product line that meets the needs of different user groups well.

We would also advise you to pay attention to those solid state drives that are produced by companies SanDisk and Micron, which uses the trademark Crucial. Both of these companies have their own flash memory manufacturing facilities, which allows them to offer high-quality and technologically advanced SSDs with an excellent combination of price, reliability and speed. It is also important that when creating their products, these manufacturers rely on cooperation with Marvell, one of the best and largest controller developers. This approach allows SanDisk and Micron to consistently achieve a fairly high popularity of their products - their share of the SSD market reaches 9 and 5 percent, respectively.

At the end of the story about the main players in the solid state drive market, Intel should also be mentioned. But, unfortunately, not in the most positive way. Yes, it also produces flash memory itself and has an excellent engineering team at its disposal, capable of designing very interesting SSDs. However, Intel is focused primarily on the development of solid-state drives for servers, which are designed for intensive workloads, have a fairly high price and therefore are of little interest to ordinary users. Its client solutions are based on very old hardware platforms purchased on the side, and noticeably lose in their consumer qualities to the offers of competitors, which we talked about above. In other words, we do not recommend using Intel SSDs in modern personal computers. An exception for them can be made only in one case - when it comes to highly reliable drives with eMLC memory, which the microprocessor giant succeeds perfectly.

Performance and prices

If you have carefully read the first part of our material, then a meaningful choice of a solid state drive seems very simple. It is clear that you should choose from V-NAND or MLC NAND-based SSD models offered by the best manufacturers - market leaders, i.e. Crucial, Kingston, Samsung or SanDisk. However, even if we narrow the search to the offers of only these companies, it turns out that there are still a lot of them.

Therefore, additional parameters will have to be involved in the search criteria - performance and price. In today's SSD market, there has been a clear segmentation: the products offered belong to the lower, middle or upper level, and their price, performance, as well as the terms of warranty service directly depend on this. The most expensive SSDs are based on the most productive hardware platforms and use the highest quality and fastest flash memory, while the cheaper ones are based on stripped-down platforms and simpler NAND memory. Drives of the middle level are characterized by the fact that in them manufacturers are trying to strike a balance between performance and price.

As a result, budget drives sold in stores offer a unit price of $0.3-0.35 per gigabyte. Mid-range models are more expensive - their cost is $ 0.4-0.5 for each gigabyte of volume. The unit prices of flagship SSDs may well reach $0.8-1.0 per gigabyte. What is the difference?

Solutions of the upper price category, which are primarily aimed at an audience of enthusiasts, are high-performance SSDs that use the PCI Express bus for their inclusion in the system, which does not limit the maximum data transfer bandwidth. Such drives can be made in the form of M.2 or PCIe cards and provide speeds many times faster than any SATA drives. At the same time, they are based on specialized Samsung, Intel or Marvell controllers and the highest quality and fastest memory types MLC NAND or MLC V-NAND.

In the middle price segment, SATA drives play, connected via a SATA interface, but capable of using (almost) all of its bandwidth. Such SSDs can use different controllers developed by Samsung or Marvell and different quality MLC or V-NAND memory. However, in general, their performance is approximately the same, since it depends more on the interface than on the power of the drive filling. Such SSDs stand out against the background of cheaper solutions not only with performance, but also with extended warranty terms, the term of which is set at five or even ten years.

Budget drives are the largest group in which completely motley solutions find a place. However, they also have common features. So, controllers that are used in low-cost SSDs usually have a reduced level of parallelism. In addition, most often these are processors created by small Taiwanese engineering teams like Phison, Silicon Motion or JMicron, and not by world-famous development teams. In terms of their performance, low-end drives naturally fall short of higher-class solutions, which is especially noticeable during random operations. In addition, flash memory that falls into drives of the lower price range also, of course, does not belong to the highest level. Usually here you can find either cheap MLC NAND, released according to “thin” production standards, or TLC NAND in general. As a result, the warranty period for such SSDs has been reduced to three years, and the declared rewriting resource is also significantly lower. High Performance SSDs

Samsung 950 PRO. It is only natural that the best consumer-grade SSDs should be found in the assortment of a company that has a dominant position in the market. So if you're looking for a premium drive that's known to outperform any other SSD in terms of speed, you can get the latest Samsung 950 PRO. It is based on Samsung's own hardware platform, which uses the advanced second-generation MLC V-NAND. It provides not only high performance, but also good reliability. But keep in mind that the Samsung 950 PRO is connected to the system via the PCI Express 3.0 x4 bus and is designed as an M.2 form factor card. And there is another subtlety. This drive uses the NVMe protocol, which means it is only compatible with the latest platforms and operating systems.

Kingston HyperX Predator SSD. If you want to get the most hassle-free solution that is known to be compatible not only with the newest, but also with mature systems, then you should stop at the Kingston HyperX Predator SSD. This drive is slightly slower than the Samsung 950 PRO and uses the PCI Express 2.0 x4 bus, but it can always be made a bootable drive in absolutely any system without any problems. At the same time, the speeds it provides are in any case many times higher than those given by SATA SSDs. And another strength of the Kingston HyperX Predator SSD is that it is available in two versions: as M.2 form factor cards, or as PCIe cards installed in a familiar slot. True, the HyperX Predator also has unfortunate shortcomings. Its consumer properties are affected by the fact that the manufacturer purchases the basic components on the side. At the heart of the HyperX Predator SSD is a Marvell-designed controller and Toshiba flash memory. As a result, without having full control over the inside of their solution, Kingston is forced to issue a warranty on its premium SSD, reduced to three years.

Testing and review of Kingston HyperX Predator SSD.

Midrange SSDs

Samsung 850 EVO. Based on Samsung's own hardware platform, which includes the innovative TLC V-NAND flash memory, the Samsung 850 EVO offers an excellent combination of consumer features. At the same time, its reliability does not cause any complaints, and TurboWrite SLC caching technology allows you to fully utilize the bandwidth of the SATA interface. Particularly attractive are the Samsung 850 EVO variants with a capacity of 500 GB or more, which have a larger SLC cache. By the way, in this line there is also a unique SSD with a capacity of 2 TB, which has no analogues at all. To all of the above, it should be added that the Samsung 850 EVO is covered by a five-year warranty, and the owners of drives from this manufacturer can always contact any of the numerous service centers of this company scattered throughout the country.

SanDisk Extreme Pro. SanDisk makes its own flash memory for its drives, but buys controllers from outside. So, Extreme Pro is based on the controller developed by Marvell, but you can find a lot of know-how from SanDisk itself. The most interesting addition is the nCahce 2.0 SLC cache, which in Extreme Pro is implemented inside MLC NAND. As a result, the performance of the SATA drive is very impressive, and besides, few people will be left indifferent to the terms of the warranty, which is set at 10 years. In other words, SanDisk Extreme Pro is a very interesting and relevant option for mid-range systems.

SanDisk Extreme Pro Test and Review.

Crucial MX200. There is a very good mid-range SATA SSD and Micron assortment. The Crucial MX200 uses the company's MLC memory and, like the SanDisk Extreme Pro, is based on the Marvell controller. However, the MX200 model is further enhanced by Dynamic Write Acceleration SLC caching technology, which raises SSD performance above average. True, it is used only in models with a capacity of 128 and 256 GB, so they are primarily of interest. The Crucial MX200 also has a slightly worse warranty - its period is set to only three years, but as compensation, Micron sells its SSDs a little cheaper than its competitors.

Budget models

Kingston HyperX Savage SSD. Kingston offers a budget SSD based on a full-fledged eight-channel controller, which is what it captivates. True, HyperX Savage uses the development of Phison, not Marvell, but the flash memory is normal MLC NAND, which Kingston buys from Toshiba. As a result, the level of performance provided by HyperX Savage is slightly below average, and the warranty on it is three years, but among the budget offerings, this drive looks quite confident. In addition, HyperX Savage looks impressive and will be nice to install in a case with a window.

Testing and review of Kingston HyperX Savage SSD.

Crucial BX100. This drive is simpler than the Kingston HyperX Savage and is based on a stripped-down four-channel Silicon Motion controller, but despite this, the performance of the Crucial BX100 is not bad at all. In addition, Micron uses its own MLC NAND in this SSD, which ultimately makes this model a very interesting budget offer offered by a well-known manufacturer and does not cause users to claim reliability.

Tearing off the covers

Millions of tablets and smartphones use eMMC, and this is also flash memory. More attention is traditionally focused on the screens and cameras of new smartphones, but the amount of disk space in them is also growing!

Demand for flash memory by device type in calendar years. Data from IDC, iSupply, HI Investment & Securities, November 2014.

In the diagram above, “Handset Embedded” is the memory built into the smartphone. Despite its small volume compared to PC SSDs, smartphones take on quantity. And is it small?

While you're moving temporary folders to the HDD, the older iPhone 6 and 6 Plus have 128GB NAND from SanDisk and SK Hynix (16nm MLC), respectively.

No wonder Apple is eating 1/6 of the flash memory pie!

Apple's market share in flash memory consumption and volume purchased in million GB. DRAMeXchange data, 2014,

I strongly encourage you to think that the technological progress of NAND must be considered in the context of demand, which is primarily dictated by the mobile sector.

Major Players in the Flash Memory Market

When buying an SSD, many people focus on the brand, which makes full use of OEM SSD assemblers like Kingston, Corsair, ADATA and other companies that do not have their own production. On the other hand, the major flash memory manufacturers may not be very interested in selling drives to end users (SK Hynix) or have a strong foothold in the consumer SSD market (Toshiba).

Who do you think makes more flash memory - Toshiba or Intel?

The answer to this question is given by the information of the DRAMeXchange resource, which I converted into a diagram. The annual revenue of the NAND market is about $ 30 billion (for reference: Nike sells the same amount :)

It turns out that Toshiba's revenue is comparable to the entire IMFT concern. But Intel's business is less dependent on flash through diversification, and the company's expertise in processors is fueling NAND innovation. Meanwhile, almost a third of the market is occupied by Samsung.

What flash memory is being released now

In two years, the technical process has stepped from 25-24nm to 19-16nm. According to the diagram below, now 90% of the delivered NAND is made using 20nm and 1xnm manufacturing processes, which you can partially see for yourself on the examples of disks from this article.

NAND production by process nodes with a forecast for 2014. Source: DRAMeXchange, January 2014.

Notice the bright red blotches of 3D NAND, the near future of the flash memory industry. The story about the new technology will be closer to the end of the article, but from now on it will be necessary to designate the memory of the previous generation with the term "2D NAND" so as not to get confused.

Let's see what the first-tier companies offer us under their brands at the end of 2014.

MLC 2D NAND

Disks with this memory are now installed in the PC of the author of the blog and most of the readers.

Samsung

By the way, Micron has finally decided on the labeling of new models. From now on, high-performance Crucial consumer drives are in the “MX” line, budget drives are in the “BX” line, and “M” drives are Micron-branded drives for PC manufacturers (older models are not covered, of course).

Toshiba and SanDisk

These two companies have historically not been very active in the manufacture of "boxed" SSDs. However, their drives have long been in demand by PC manufacturers (up to Apple), and many OEM assemblers install memory in their SSDs.

However, in recent years, partners have become more active in the consumer market under their own brands. So, Toshiba released discs with the cryptic name Q Series Pro on 1st generation 19nm MLC NAND (these were also sold under the more sonorous third-party name Strontium Hawk).

In SMART, some SSDs (for example, Intel and Kingston) have a special Total NAND Writes attribute for this. In other drives, you have to look for workarounds. For example, Samsung has a Wear Leveling Count that gradually decreases from 100 to 0. Therefore, you can sequentially write incompressible data and monitor the changes in the indicator. Knowing the average write speed and its duration, you can estimate the number of rewrite cycles and the overall endurance of the drive.

The AnandTech site, after their tests, gave their estimate of 840 EVO at 50GiB writes per day, which is reflected in the table.

On the one hand, these figures are based on a factor WA = 1 (sequential write only), and in home loads it can be 1.5 - 2 due to random operations. However, the daily recording volume is taken with a solid reserve. It is 2.5 times the minimum size of 20GB, which is now guaranteed by all manufacturers (further discussion of this issue will be in the next article).

Meanwhile, reaching the wear threshold in SMART does not mean the death of the drive at all (unless it is included in the firmware). As you saw above, experimenters go further, writing data to disk until the NAND resource is exhausted. At the time of publication of the article, a Japanese site was live streaming the execution of the 840 EVO, which eventually recorded 6 times more data than the manufacturer guaranteed.

Continuous recording on 840 EVO - the disk withstood 750TB (those who speak Japanese will tell you the exact cause of death :)

By the way, on the same site there are current and final results of killing other SSDs, I recommend that you read it.

For home users, the endurance of TLC should be enough for the eyes, and we will check this with you next time.

However, the reputation of TLC NAND durability in the eyes of potential buyers has been spoiled by various "horror stories", so marketing tricks are used. Last time I noticed that Samsung used the term 3-bit MLC instead of TLC in their diagram. The company generally avoids the term TLC in relation to its NAND.

Having tested the new memory on consumers, the company released the 845DC EVO in the summer of 2014 in the corporate segment, where rewriting cycles are not so critical, because. reading takes precedence over writing.

Quote from Samsung 845DC EVO specs

Veils are torn off by the mention 3-bit- MLC has 2 bits stored in a memory cell, and TLC has 3.

The Future of TLC 2D NAND

At the end of 2014, TLC memory comparable in quality to MLC is produced by two of the top four flash memory manufacturers, if you count alliances.

• Samsung, which sets the tone for the industry, has already released two generations of discs (840 and 840 EVO), and there will be no third (more on that below)
• SanDisk has a 19nm TLC drive and ramps up production on a new 15nm process
• S.K. Hynix has already received engineering samples of 16nm TLC and is preparing to enter the market with it in the first half of 2015
• Micron receives samples of 16nm TLC and promises a disk with this memory in the summer of 2015 (Intel probably has similar plans)

A huge part of this memory will go to smartphones and tablets. As for the PC, in addition to the disk from Micron, OEM drives with resonant brands based on TLC NAND from Toshiba/SanDisk may appear in the near future.

3D NAND

Samsung's innovation goes beyond its leadership in TLC 2D NAND. The company is already making next-generation flash memory commonly known as 3D NAND (Samsung's marketing brand is 3D V-NAND). This technology is designed to reduce the cost of manufacturing flash memory in an environment where there is nowhere to further reduce the crystal along the X and Y axes, which actually happened with 2D NAND.

What is the essence of 3D NAND

3D NAND has a third dimension along the Z-axis, since the memory cells are placed vertically (Samsung's "V" prefix is ​​just for Vertical). But this does not mean that the crystals are stacked. With 3D NAND, the overlay is done at the wafer level, so each crystal contains several layers of cells- hence the concept of 3D.

At Samsung, the first generation of V-NAND memory consisted of 24 layers, but by the summer of 2014 their number was increased to 32

The introduction of the vertical axis removed dependence on the X and Y axes. Since there is no longer a need for such a small die size, Samsung has returned to the 30 or 40nm process technology (figures vary depending on the source).

One way or another, now not only the size of the cells is larger, but also the distance between them. This is important because when the crystal is compressed to 20nm, there is an acute problem with charge flow from one cell to another, which results in errors, which are exhaustingly fought with the help of EEC. On the other hand, as the 2D NAND process technology approaches 10nm, the cost of lithography equipment offsets the savings from die compression.

Samsung 850 Pro

In the middle of summer, the company released a model 850 PRO, which has a 32-layer 3D V-NAND with a die density of 86Gbit. The disc combines high performance with fantastic endurance.

Samsung 850 Pro is the first drive with 3D NAND

The company guarantees 10 years of disk life or 150TB of recorded data. In terms of warranty period, only SanDisk Extreme Pro can be compared with this, but not a single competitor is ready to be responsible for such recording volumes. What's more, a Samsung spokesperson told AnandTech that the firm has no plans to deny warranty for recordings over 150TB in client PC.

A Samsung employee also claimed that the company's internal testing is 850 PRO 128GB, which has already recorded 8000TiB.

A person cannot write down so much in his entire life, unless he specifically sets himself this goal. However, this is what I decided to do. rugger, a whirlpool forum member who has previously done similar experiments with other drives. For 44 days he continuously recorded data on 850 Pro 128GB and stopped at around 1PiB (1000TiB).

The 850 Pro took a petabyte of data to the chest (F1) without even using spare blocks (B3)

According to SMART, the Normalized Wear Leveling Count (B1) dropped another 740TiB to its low point, but the drive continued to function properly. He subsequently died while undergoing further tests on him.

3D V-NAND is the only fundamental change in the 850 PRO from previous Samsung models. Its heart is a three-core MEX controller, tested on the 840 EVO, and the interface is still the same SATA III. All speed performance of the 850 PRO is at the highest level, and even with the standard 7% spare area, the drive demonstrates impressive performance stability.

Samsung 850 EVO

At the time of publication of the article, Samsung did not have such a disk, so there were speculations before. The disc came out as expected. Back in the summer of 2014 at the Flash Memory Summit, the company announced plans to release a 32-layer 3D TLC V-NAND, which began mass production in October.

850 EVO prototype shown at IFA 2014 in Berlin in September 2014

The 850 EVO was clearly a match for the 850 Pro, similar to the previous 840 series. The upper price segment is MLC NAND, and the lower one is TLC NAND. The only difference is that the new generation drives use 3D V-NAND.

3D NAND removes the main problems of TLC - rapid wear and low performance compared to MLC. The 850 EVO disc should turn out to be very interesting in terms of price / quality ratio. And I wouldn't be surprised if Samsung gives it a 5 year warranty. Time will tell!

The Future of 3D NAND

In terms of bringing new technologies to light, Samsung is now the undisputed leader in the flash memory industry. The company has a full cycle of production of solid state drives and is not tied hand and foot by alliances, which gives freedom of action in the market. As a whole on the market alignment for the end of 2014 such.

• Samsung is already releasing MLC 3D NAND with 86Gbit die density (used in the 850 Pro drive) and TLC 3D NAND with 128Gbit die density.
• Micron said on a conference call with analysts in September that she received 3D NAND samples with the industry's highest die density of 256Gbit. Mass production is scheduled for the second half of 2015.
• Intel announced at a meeting with investors in November that it is going to release the same memory in the same time frame as Micron.
• S.K. Hynix said in October that it had sent samples of the first generation of 3D NAND to customers and was starting to develop the second and third generations of memory.
• Toshiba and SanDisk plan to start production no earlier than 2016 due to the lack of suitable capacities. For the release of 3D NAND, they only started building a new $4.9 billion factory on the site of the old factory in the fall of 2014.

One way or another, the expansion of 3D NAND is inevitable. The forecast below, in my opinion, is overly optimistic, but it was made a year ago.

3D NAND supply forecast as a percentage of total NAND. Source: IHS, October 2013.

You already saw the following chart last time, but now I want to put it next to the 3D NAND prediction.

Global NAND shipments by memory type. Source: Samsung, 2013.

Taking into account the demand of the mobile market, the dominance of TLC is understandable. It is important to understand that these two diagrams do not contradict each other. Even with the transfer of production to 3D NAND, TLC memory will remain cheaper than MLC, and therefore will be more in demand on the market. In other words, TLC 3D NAND is the future.

Which SSD to buy now

In this article, I have mentioned new SSDs released only by flash memory manufacturers. It is they who control the market for solid state drives, and the volume of NAND output when changing the process or technology is always limited at first.

Therefore, Tier 1 companies may well compete with OEMs on price, as SanDisk and Micron do. For example, when I was looking at a 250-256GB drive in September 2014, the latest Ultra II and MX100 with TLC NAND were about the cheapest on Amazon and NewEgg.

300nm Micron NAND wafer, manufactured in 16nm process technology, has a capacity of almost 6TB

On the other hand, improving the reliability and endurance of 2D NAND is becoming an increasingly difficult task, and firms with their own production of memory and at least firmware for controllers are better at it.

about the author

1. Controller, price - 50/50.
2. I bought a SmartBuy Ignition 2 60Gb laptop. But, as it turned out later, in the new revisions of Ignition 2 60 GB, there are only four NAND crystals. Hence, the linear write speed is noticeably lower than on the old revisions, this cannot be fixed with the new firmware. I was a little upset, but the performance on 4K reading is still better than that of the HDD, which simply did not have the strength to work with. But it cost much less than all the others.

Um… i.e. Do you consider the Phison controller an advantage worthy of becoming the second selection criterion? Meanwhile, your 60GB drive has Micron 16nm memory. Compare with what Micron itself does. What I mean is that your drive is lower not only in speed, but also in endurance. In general, this is a very budget option (just stating a fact).

• Valery

  They are also produced on Toshiba 19nm 128 Gbit.

  I also took 2 pieces for myself on Phisons and a quick memory config. Quite a normal choice.

  mikor

  I didn’t think about endurance at all, because. I think that this is an absolutely ephemeral criterion, which, in fact, is proved by the tests of some enthusiasts. As for the controller, Phison seems to be better than SF anyway, well, I repeat - it had no competitor for the price.

  smart sound

  Budget 8 thousand. I work with audio and video in editors.
  Is there anything better for this budget?

Denis Bogachyov

When I bought an SSD for myself almost a year ago, I was guided by articles from this blog. As a result, I took OCZ Vertex4, because OCZ has its own controller, and was completely satisfied. The speed is on the level, the test results are also encouraging.

Just the other day, I bought my wife the 120 GB SanDisk Ultra II mentioned in the article. Cheaper than him were only all sorts of Kingmax's and other Smartbuy, but I decided to trust the office, which itself produces memory. That is, in this case, my choice was most influenced by the price and the availability of my own memory.

Installed, transferred the system according to the guide from here :) Everything went quickly and quite simply, the speed of work pleases, subjectively I would not say that there are any differences from the work of my Vertex.
But itching in one place did not allow me to enjoy life, and I tested the SSD using Crystal Disk Mark. And here he made me a little upset. Parrots gave noticeably less than OCZ. However, I'm still not sure if this is really his normal speed. Perhaps specifically my drive is messing up?

So when choosing the next ssd, I may again prefer the manufacturer with my controller.

Alexey Arkadiev

I chose an SSD for a laptop, and paid attention not only to performance (it's just not very important to me), and reliability (all data is in the clouds, SSD failure is not terrible), but first of all to power consumption. Attention was immediately on Samsung, it eats the least in tests for power consumption. As a result, I took 850 pro 512GB.

Maksim

Last fall I bought 2 SSDs for home and work.
Since he did not have exhaustive information, he was guided primarily by the brand

For the home, I took INTEL SSDSC2CW120A3 despite the price of more than 7000r. First of all, high speed and reliability were needed.

And for work I chose KINGSTON SV300S37A120G already guided by the price-quality ratio, where neither high speed nor fault tolerance was needed.

Yuri Moskalenko

A very interesting article, .. thanks for being so detailed, ..
1. when I chose the SSD drive, .. honestly, .. I didn’t sleep for three or four nights, .. I didn’t want to overpay and I didn’t want to take the budget, .. the second question is life and durability, there are a lot of offers, .. the choice is large, ..your article about myths put an end to my suffering,..further,..when the disk was purchased, the Plextor 128 M5 PRO had a question about its operating time,..and again I was shocked,..but after reading the article,..calmed down ..it was this disk that attracted my attention, more precisely, reviews about its work, ..I didn’t delve too deeply into the manufacturing structure itself, ..I think it’s enough for my age, ..Vadim, by the way, you didn’t mention this model in your article, ..it would be interesting to hear your opinion..well, regarding the criteria,..honestly,..there was no talk of any savings when buying a disc

artem

I'm surprised that in the survey there is no option "I select the entire device and cannot influence the type of drive in it." I understand that such a scenario is not very informative for you. But statistically it should be one of the most common.

Evgeny Shiryaev

I chose according to the price-volume ratio, so that it would be cheaper and more spacious. So that the brand is at least a little familiar, so that this gadget is on sale in a trusted store. Bought as a result Plextor PX-128M5Pro. At the time of the purchase (somewhere in the spring of this year), I knew almost nothing about the design features of the SSD, I learned a lot after buying it here :) Next time, I may approach the choice more consciously.

Alexander Sokolov

I chose my first disk on the recommendation of a friend - it was OSZ Agility III 60 Gb. I took it because of the "highest speed", although after switching from the HDD, the increase in speed would have been in any case. And by the way, I saw a greater increase when switching to Windows 8.1 from the Seven than when switching from HDD to SSD (but when I upgraded the system hardware 5 years ago to a fresh one, I did not feel an increase in the OS - in toys only if)
But I took the second SSD based on the recommendations of this blog and other sites - it has already become Samsung 840 Pro 128 Gb - it already has its own controller, speed and price / quality ratio - in my opinion a very successful model.

gorinich

more than a year ago, when choosing the first ssd, my main criterion was getting the maximum increase in speed with minimal investment (not in the survey). reliability was in second place (in this regard, the type of memory and warranty are what I paid attention to). pci-e was not considered because of the price and then the problems of boota from them. the choice was a pair of Samsung 840Pro 256 Gb (minimum volume with maximum read/write speed). I do the settings according to your blogs (for example, disabling fragmentation), but it happens, and contrary to your advice (I always remove the pace and swaps from ssd to ram with image storage on hdd). I'm very happy with the result so far:
http://img.maryno.net/images/6b4d96f90185050a2144901a21828ee6/2f1719bed874f4ca688a1dd03dcbc84f.jpeg
http://img.maryno.net/images/6b4d96f90185050a2144901a21828ee6/262092319657d22488d75c4377c223b4.jpeg

Now the question is brewing about ssd for a gaming laptop. requirements have shifted slightly. the main thing is the volume: less than 500 Gb is not interesting, since it is problematic to get the necessary space with arrays or hdd on a laptop. price came in second. maximum performance and reliability for a small amount - on the third. I was leaning towards the 840EVO, but the reliability was somewhat depressing. after reading this blog I'll wait for the 850EVO, it looks like an upcoming winner by my current criteria.

P.s.: Vadim Sterkin, thank you very much for your blogs. agree / disagree with some conclusions - that is a secondary issue. the main thing is the colossal work of collecting, categorizing information and enlightening dark minds. I periodically log into your old blogs for some simple advice that I myself did not think of. but I know where they are :)

Dima Vasilich

Hello Vadim, forum users. Thanks for the article - as always, on the level.

This year the Samsung 840 pro. The choice fell in the order of interest, positive reviews + good statistics in the reviews + I wanted to try out the RAPID mode (it’s not noticeable to the eye, rather the opposite - there is some kind of thoughtfulness)
I had my eye on the 850 pro, but the piggy bank does not keep up with the price tag (of course, this is not a complaint, so, thinking out loud)

Vitaly

A few months ago, I took my mother a solid-state monoblock, since the hard one in it went into trouble. I took the cheapest 64GB one I found at the time of purchase: 64GB SSD, SanDisk, SDSSDP-064G-G25, 2000 rubles. It works fine, faster than it was with the hard one, it has no disk requirements, everything is on the web.

Dima Vasilich

Vadim Sterkin: Dima, I wonder about RAPID thoughtfulness. In what tasks?

When 8.1 was installed on it, thoughtfulness was observed when launching applications pinned to the taskbar, but, to a greater extent, sites pinned to the taskbar.
I can be wrong, I think that this is more likely to save a resource than to speed it up. But it’s hard to be objective, because the front of my PC’s work is not large - in some applications / games it may make sense.

sergey888

When choosing an SSD for myself, I was based mainly on user reviews on the Internet, as it turned out, the least negative reviews were for Plextor drives, and only then I chose an affordable 128M6S and so far I am even very pleased with the purchase)

Alexander [Mazdaischik]

Guided interface (mSATA - it is in the laptop, but it was empty when buying), price, volume (to keep both the system and all sorts of different files on the disk, and so that there is still room), declared speed, reviews under the goods in the store (that is another criterion , Yes). I was only interested in speed in one aspect - fast enough compared to other drives with a comparable price and volume.

Not interested: controller, memory type, service life (bought, expecting that after 3 years the disk may fail). I didn’t want to puzzle over technical details at all, and so the performance gain is gigantic. (Given that the native hard drive is slow - an external terabyte drive via USB 3.0 even overtakes it, judging by the task manager).

chose Plextor PX-256M6M, now I have a native 500 GB hard drive in my laptop and this SSD. The system was transferred using the recommendations of the blog.

Dmitrij "FiLDiX" Filatov

I bought myself, along with a PC upgrade, my first 2 SSD drives Samsung 850 Pro 256GB for RAID.
My choice was driven by the following factors:
Price;
Brand;
Availability of own memory / controller / firmware from the manufacturer; *
Memory type (MLC/TLC); *
Warranty period (5 years or more); *
Advice from a friend or acquaintance;
Recommendations from other sites.
* voted
P.S. As they say: "I'm happy as an elephant!" =)

• Dmitry, why do your criteria for commenting and voting differ? Why is price first if you bought one of the most expensive drives?

  • Dmitrij "FiLDiX" Filatov

    Vadim, I would not say so... Even if you had published this article earlier, my choice would not have changed one iota. When buying components, I always take into account my needs with a reserve for the future, but I recommend based on the appropriate choice for the specific needs of end users.
    Prices in my city differ significantly from large cities, so this should also be taken into account.
    I save on everything I can. Luckily I have friends from China. And there all the equipment is much cheaper.
    Ordering through eBay or Amazon does not suit me because of my bitter experience. If something is wrong, then, accordingly, there is more trouble than the money saved, and overpaying for extra. I'm not used to services.
    P.S. So your SSD series is very helpful and easy to understand for less advanced users, or as a start.
    P. P. S. I remembered that last summer I went to my friend in the village. So, there they have a “predatory” attitude of geeks towards mere mortals, who are not boom-boom at all in all this chaos of the IT world. I had to solve a small problem related to accessing the Internet via a 3G modem from Beeline, which consisted in the fact that I just had to uninstall two versions of the software and install a new one. The problem arose in connection with the use of modems (of which there are two) with different software versions. It took about 5 minutes. It seems to be nothing complicated. But the “village” IT specialist, after examining the PC, demanded 1,500 rubles (a good amount by their standards). And I saw the problem only in reinstalling the OS. But I understand that he did it on purpose. I'm not even talking about what price tags they have for PCs, components and peripherals.
    So here it is... =)

begem0t

Hello Vadim! I recently came across your blog and immediately subscribed. A lot of useful information presented in an interesting way, thanks.

I'm just going to buy an SSD for the first time in a new desktop. The budget for the drive is small, so I really liked the Crucial MX100, which was just mentioned in this article. Perhaps the best price for 256 GB. But there are a lot of bad things about him now on the net. And the guarantee is small, and the speed is useless, and on overclockers they generally write about more frequent cases when the drive leads to BSOD and disappears in the BIOS.

I would like to ask you and other readers, is everything really so bad with him?

Anton Ermakov

Hi Vadim! The purchase criteria for my OCZ Vector 150 120 GB were:
a) having your own controller
b) MLC memory type
c) warranty period 5 years

Bought on January 5 this year. Hard Disk Sentinel is the only program that shows the level of his HP (health).
Current stat = 73% HP
Recorded 5.66 TB
Approximately 860 days left before death.
18 bad sectors.
No other program (tried ssd life and crystal disk info) shows its vital signs normally. Have you come across OCZ Vector?
Thank you for your work, it's always very interesting to read!
Sincerely, Anton.

• Anton, quite sound criteria. I didn't have OCZ discs, and in January 2014 I definitely wouldn't buy them (the entry was posted on December 23, 2013).

  Thanks for reading my blog!

  • Anton Ermakov

    Vadim, regarding the bankruptcy of the company. I tormented the service manager for a long time until he gave me:
    - You bought the device from us, not from OCZ, and therefore we assume warranty obligations.
    Sincerely, Anton.

    • Valery

      OCZ has a fairly loyal RMA policy in Russia.

      The safety of the guarantee / receipt is not required. Change by serial number. At least that's what the manufacturer says.

      Anton, Valery,

      The warranty is not the only aspect. Let's say a problem has been discovered in the operation of the drive, as in the case of the 840 EVO. Samsung released the corrected firmware within a month. I'm not sure that a bankrupt company will do it as quickly. And the service center / RMA will not help you here.

      P.S. Anton, square the photo in the VK profile is better translated into avatars on third-party sites :)

Valery Yuri Borisovich At the beginning of 2012, while assembling a new computer, I bought an Intel, I think, 520, 128 GB. It cost then 9 thousand, quite expensive. The speed was very satisfying.
By the middle of 2013, it became clear that it was necessary to increase the size of the SSD in the laptop - the working files and the system no longer fit on the old one. The choice fell on the Samsung 840 PRO with 256 GB, which has already been working in the laptop with the only disk for more than a year and a half. In September, for the same reason, I installed the exact same one in the desktop instead of the first Intel.

Konstantin

I bought my first Intel x25-m 80GB SSD in early 2010. Then I knew little about SSD and the technologies used, I remember that at that time only Intel used a 10-channel controller and this gave a significant performance advantage. Then the prices for SSD "there" were so low that I, spitting on the warranty, bought the drive on ebay.
Subsequent discs were already bought in local stores and in all cases the determining factor was different.
Crucial m4-256 chose for the maximum (for 2011) volume and decent performance. Unfortunately, the Corsair Performance Pro 256GB was out of stock at the time of purchase.
Plextor m3s-128 - in my wife's laptop: 128GB (64 is also enough, but it would be back to back), height 9mm, power consumption.
Crucial m4m-256 - for a laptop with mSATA: the actual form factor, power consumption and volume.
Basically, we studied the test results and reviews of the owners for massive problems, and looked at the types of memory and warranty only for reference. Somehow I have already got used to the idea that drives are consumables like cartridges, so I just make a backup on a NAS.

Alexander M

At the beginning of this year, I bought a Plextor-M5Pro for a laptop and a Plextor M5S for my wife for a desktop (well, I'm also a little geek :), both 256 Gb each. The brand, the presence of its own firmware (on the recommendation of the site) and for another reason - I already had one of these and completely satisfied (and satisfied). Although now I would look in the direction of Samsung, only the need is not enough.
I would also name among the important reasons when choosing a particular disk speed, test result. I would look at reliability not in the sense of how many write cycles the cells will be erased, but on how much they write about the marriage of the model in the reviews

Lecron

As I see, many people choose them not rationally, but rather emotionally - wow, cool, faster. Himself the same. But he indulged and sold it six months later. And all from what he decided to evaluate, and how much he reduces the time of work. Work, which consists of tasks, each of which, respectively, of the stages. The result is disappointing - less than 1% of the time.

I cloned the system back to the HDD and recorded tracks in the System Monitor over the weekend - processor load, disk queue, disk exchange speed (there seems to be a counter for the amount of data transferred, it may come in handy for your future article). In nnCron, he kept a log of user and active program activity. It was difficult and tedious to analyze the result, but the results were approximately as follows:
- total activity time - about 16 hours.
- activity other than the role of the media center (XBMC with remote control) - about 10 hours.
- an extremely pessimistic time when disk activity was the brake - 10 minutes. In reality, 2-3 times less.

Yes, everything they write in the reviews is true. And at the same time false.
Programs? Yes, they load faster. But they work pretty much the same! Moreover, they work several orders of magnitude longer than they are loaded from a slow disk. Do not forget that the slowest operation - writing - usually occurs in asynchronous mode, with caching. Copying? Usually limited by the interface (network, USB), or even the speed of the flash drive. With sequential access, hards can handle this quite well. Antivirus and more? Background activity with the lowest priority. Etc.

Began to look for real tests. Found only http://www.thg.ru/storage/test_ssd_v_ofisnih_prilozheniyah/print.html
Which largely confirms my conclusion about the minimal impact on the work as a whole. I agree to overpay 20-30% of the cost of a gigabyte for such an acceleration. Well, let them pay extra for noiselessness, insensitivity to temperature and vibrations, but in total no more than 2 times, a maximum of 2.5 times. Not more.

PS. This is only about my home computer. There are tasks for which SDS are extremely necessary, but there are not so many of them.

• Konstantin

  In general, your calculations are correct, but I cannot agree with this approach to assessing the benefits of an SSD.
  For me personally, SSD is good not for sequential write and read speeds under the SATA3 ceiling, but for low latency during random reading, which increases comfort when working with a computer, the ability to pull a working laptop out of the docking station and, closing it on the go, put it in a briefcase and not worry that the disk may get sick from such treatment.
  Did the transition back to the HDD not cause you discomfort?

  • Lecron

    I don't convince anyone. I'm talking about a personal home desktop. Didn't see the difference.
    If we remove from consideration the download speed of programs, the rest is at the level of measurement error.
    The reverse transition, exactly what caused only a slight discomfort, but did not increase the time to solve problems. Moreover, the discomfort was only at the stage of direct comparison. After a week, the impressions smoothed out and the discomfort went away.

    Do you know what hand memory is? When the mouse or the fingertip on the keyboard is in the right place, even when the control / screen has not been drawn. There was no such thing. My speed of work, reading material from the screen, input, operating the interface, was not limited by the speed of the disk.

    Cases of need for SDS also know personally. Several. But this is clearly not an ordinary "home" computer, in the absence of a NAS in the home infrastructure.

    • Literally an hour ago I was talking with my system administrator while we were setting up one thing. And he says something like this

      I assembled a home PC for myself - a good CPU, a RAM car. But I’m running a virtual machine and I’m sitting watching how stupid it is, because I have a hybrid disk

      Of course, virtual machines are unknown to an ordinary home computer, but an ordinary home computer enthusiast- more than.

      And here is what fell into the mail from a reader yesterday.

      I came to you by accident, deciding to ask how my drive is doing, I came across an article about 12 ssd optimization myths. And then, like a snowball, I read for several hours in a row. Thanks to your notes during the next upgrade, I made a choice towards 8.1. When the system booted up in less than 10 seconds, the jaw dropped.

      This is an ordinary home computer and user, because only ordinary people have this effect on boot time (experienced ones send them to sleep without wasting extra time).

      The issue of overpayment per gigabyte is always raised by those who are satisfied with the HDD. But no one buys a 128-256GB HDD (and even more so 64GB) now, as do the owners of solid state drives, who also don’t just buy terabyte SSDs. Hard drive rules if you need 2-3 TB vaults.

      Therefore, I believe that the combination of a fast SSD and a capacious HDD is optimal in terms of performance and disk space at the same time, and for most home users.

    • Konstantin

      I agree with you that no SSD will increase the performance of the human-computer system, and yes, the computer “waits” for my actions orders of magnitude more often than I do for its reaction to my actions.
      SSD "only" smooths out the plugs in the responsiveness of the computer, makes interaction with it more pleasant.
      This can not be called a necessity, it just turned out to be so valuable for me that I put an SSD not only in home computers, but also in a work laptop. And backups and archives have moved to NAS, where there are regular disks.

Lecron

Incidentally, in the words 3-bit MLC instead of TLC"There is no trick. And even vice versa.
It looks more like just a reasonable deviation from the usual, but erroneous names, when Multi Level was erroneously fixed in the heads, exclusively for Dual Level Cell. A similar mistake is when LCD screens are called TFT screen. The mention of TFT was an advantage in the transition from passive to active matrix, but now it does not make sense. After all, AMOLED and even eInk have a TFT control matrix.