Hybrid sshd drive ssd buffer size. Hybrid hard drives SSHD. Pros and cons. Low - technology matters

A person does not know what a hybrid hard drive is. The fashion for combining several fundamentally different technologies in a single device is not new.

For example, cars that selectively use a traditional internal combustion engine or an electric drive for movement have become quite commonplace. Such a solution makes it possible to get by with "little blood" in the gradual transfer of technology to a new alternative. Hybrid hard drives fully comply with this rule. Let's take a closer look at this issue.

Retired ... or more alive than all the living?

Currently, in the field of computer technology, the main device for long-term storage of information is a hard disk or hard drive (English HDD - hard drive disk). Its design and principle of operation are quite simple: several discs made of a non-conductive electrical material are placed in a small metal case. From all sides, the surface of each of them is covered with a deposited magnetic layer. The disks are strung on a common axis-spindle, rotated by an electric motor at a constant speed (in some models, it can change in steps, depending on the intensity of use). A special mechanism moves the frame with the write / read heads over each side.

When writing, parts of the surface are magnetized, and when reading, the reverse process occurs - a current is induced by the magnetic field and converted by the controller into a data stream. For decades, the technology has been tested, "childhood diseases" have been eliminated.

A dark horse

However, with the advent of solid-state memory, alternative solutions appeared on the market, in which there are no rotating parts, and the recording is done by changing the position of the floating gate in the transistor. Such drives are called SSD (from English. Many people believe that based on solid-state memory cells, the performance of which is much higher than that of HDDs, they will gradually replace classic hard drives. It is too early to talk about a global transition (despite the fact that there are hybrid HDDs). And that's why :

The cost of one gigabyte of disk space for an SSD is several times higher than this parameter for an HDD (the coefficient can be obtained by dividing the price by capacity);

With reliability, not everything is so simple. Each solid-state drive is characterized by an acceptable number of write / read cycles;

The technology is too new, it is constantly being improved, so a device bought yesterday may be hopelessly outdated today (take at least the support of the TRIM command).

Hybrid hard drive

Understanding that it is premature to talk about a complete change in technology at present, manufacturers have proposed a compromise option that combines HDD and SDD. The basis for the design of such a device is magnetic disks (a hard drive with its low cost and ... not too impressive performance). The peculiarity is that the hybrid hard drive also contains chips and an SSD controller. Of course, there is no need to talk about hundreds of gigabytes, usually the volume is limited to ten. That is, the main volume falls on magnetic disks (for example, 750 GB), the SSD capacity is 8 GB, and, of course, the cache (32-64 MB). Hybrid during operation copies the most requested data to fast solid-state memory, then working with it. In other words, the SSD in such a solution is a second-level cache.

Many have already heard about the new hybrid hard drives, but most will wonder if they are worth buying? Or maybe instead of hybrids, it’s better to take a small SSD drive (or there is a lot of money for a large one), install a system on it, and install a regular hard drive for data? Now I will try to shed light on this issue.

After my laptop fell off the table, the hard drive had to be replaced. There is no space for a separate SSD drive in the laptop, so you can only plug one device into it. I settled on a 1TB Seagate ST1000LM014-1EJ164 hybrid hard drive and about 8GB SSD cache. This is certainly not as much as we would like, but so much is better than nothing at all. Such a hybrid drive cost me almost 7,000 rubles.

The cache of the hybrid disk is completely hardware-based and there are no programs to configure and optimize it. Programs and files that are frequently used, including system ones, are cached.

Benefits of a hybrid hard drive

I list the advantages that I was able to identify when using a hybrid from Seagate:

• when using "quick start" Windows, the system loads 25-30 percent faster,
• applications that we often use run several times faster,
• copying files up to 500 MB, even within different logical drives, occurs at a high speed, approximately 200-300 MB / s (I think the file is first copied to the cache, and then transferred to the hard drive during idle time),
• the whole machine runs faster and there are fewer bottlenecks.

Cons of a hybrid drive

We note some disadvantages, but they are not critical:

• the cost is almost 2 times that of a conventional hard drive,
• low amount of SSD cache (in general, there are all sorts of disks, they have both 32 and 64 GB, but the cost is appropriate).

Conclusion, is it worth buying?

Let's move on to the most important thing, and here I have two answers, and they depend on your computer operating conditions.

I think it's worth buying them only for laptops when there is no way to put a second separate drive in it. If you have a desktop computer, and there is space in it (usually it always is), then it would be best to take a separate SSD drive, from 64 GB to 128 GB (this is if you plan to keep only the system on it). And if finances allow, then you can fork out for a 1-2 TB SDD, I think it will be great.

Solid-state drives (from the English solid-state drive, abbreviated as SSD) have come to replace the traditional storage of information - hard disk drives (hard disk drive, HDD). SSDs do not use magnetic disks that rotate (as in HDDs), but fixed flash memory chips, similar to USB flash drives. However, with its many advantages, solid-state drives have yet to completely replace hard drives, even in laptops, let alone desktop PCs. The main disadvantage of SSDs is their high price: a gigabyte of their volume costs much more than an HDD. Therefore, we will tell you in which cases it is better to choose an SSD, HDD or hybrid solution.

Benefits of an SSD

The main advantages of solid state drives over hard drives are:

• high performance;
• physical resistance.

For example, the sequential read and write speed of a 2.5-inch laptop HDD is 100 MB/s, and a 3.5-inch desktop HDD is 150 MB/s. The speed of random read-write (files are scattered over the entire surface of the disk) in the HDD can be ten times lower than sequential.

An SSD is another matter: even when connected to a motherboard with an outdated SATA II interface, the linear data reading speed will be less than 250 MB / s. And it is worth upgrading to SATA III, as the speed will increase to 400-500 MB / s. In turn, the linear write speed of an SSD, depending on the model, can either be equal to the reading performance or be half as much (but still higher compared to the HDD). And thanks to minimal data access delays (SSD, unlike HDD, you do not need to move the read head across the surface of the disk), the speed of random read-write is also significantly higher.

With no moving parts (electric motor, read heads), solid state drives are not afraid of exposure to strong vibration and shock. This allows, for example, to work on a laptop while driving a car on a bumpy dirt road. However, it’s not worth it to crash test an SSD so that you don’t have to mourn the information that was stored on it later. They are less afraid of SSDs and overheating: operating temperatures up to 70°C are acceptable, while HDDs are limited to 60°C.

Advantages of HDD

The good old hard drives also have their advantages, namely the possibility of repeated overwriting of data and an advantageous ratio of price and volume. With very active use of SSDs (server PCs), memory blocks can be “wiped to holes”. Depending on the type of flash memory - TLC, MLC or SLC (second mass) - blocks can be overwritten from a thousand to hundreds of thousands of times. Worn out blocks are automatically blocked, causing the SSD to lose volume over time.

Traditional hard drives, on the other hand, allow you to overwrite data much more times - the number goes into the millions. Therefore, it is not so much magnetic disks that fail in the HDD (although bad sectors also sometimes appear on them), but mechanical elements. However, data is not overwritten as often on home and office PCs as it is on servers. Unless the registry of the Windows operating system reads and writes data continuously (it is not surprising that bad sectors on the surface of the HDD most often appear exactly at the location of the registry).

But when it comes to price, it becomes impossible to argue with the victory of hard drives. At the moment, for $100 you can buy a 120 GB SSD, a 2.5-inch 1 TB HDD, or a 3.5-inch 2 TB HDD. The difference in volume between SSD and HDD for the same price is tenfold, which is why you should pay attention to hybrid solutions.

Benefits of hybrids

A hybrid is called a PC disk subsystem, which combines the advantages of SSD and HDD - high speed and large volume at a reasonable price. There can be three options for a hybrid disk subsystem: an SSD large enough to install the operating system and programs (60-120 GB) plus a large HDD for storing photos, videos, music and games; large HDD plus a separate SSD of small capacity (20-32 GB) for caching frequently used programs; and finally hybrid accumulated (HDD plus a small SSD in a single package).

The first version of the hybrid disk subsystem is, of course, the best, but also the most expensive - it will cost a good $200 (HDD+SSD). Those who want to save money should choose the second option - a small SSD for caching costs only $50. However, for SSD caching to work, a motherboard that supports Intel Smart Response Technology (Intel Z68, H77, Z77, H87, Z87, H97 and Z97 chipsets) is required. Hybrid drives (SSHD) are best suited for laptops, where you have to sacrifice a DVD drive to install separate SSD and HDD.

SSD Form Factors

Not all SSDs are made in the popular 2.5-inch format (an additional mount is required to install in a 3.5-inch slot). In addition to 2.5-inch, there are 1.8-inch models with a SATA connection. They are used, however, in the so-called embedded systems, such as on-board computers of premium cars. For thin laptops (ultrabooks), extremely compact mSATA and M. 2 form factor SSDs have been created. And for computer enthusiasts who are ready to pay any money for the most powerful components in the world, solid bodies are offered in the form of PCI-Express 3.0 expansion cards (linear read speed - recording reaches an impressive 1000-1500 MB / s).

Migrating to SSD!

Installing a solid state drive speeds up the PC much more than, say, upgrading the processor, even if it has all eight cores. Reducing the boot time of the operating system, falling asleep and waking up the PC, launching programs (even a web browser and a text editor) is hard to miss. And you can transfer Windows from HDD to SSD, along with all installed and configured programs, with just two mouse clicks using the free utility EaseUS Partition Master Free. Or just contact ours for help.

SSHD hybrid drives - what kind of bird?

• King Servers Blog

In our work, we often have to deal with a variety of storage media, including hard drives and solid-state storage media. At the same time, sometimes quite unusual devices that are not common everywhere come across. For example, SSHD - hybrid hard drives. Probably, there are people on Habré who are well acquainted with this type of information storage, but there are also those who have not even heard of such “hybrids”.

So, hybrid hard drives are, first of all, a compromise solution that allows both to increase the overall performance of the system in which they are installed, and to reduce the price of such a system.

After all, despite the widespread use, solid-state drives are still quite expensive, and it is unlikely that the moment will come when the price of such drives will drop significantly in the near future.

Ordinary hard drives are inexpensive, for the most part, but their performance is limited, you cannot “jump” above a certain limit. Therefore, hybrid hard drives appeared. SSHD appeared a few years ago, and at first they were pure exotic, which few people took seriously (and few people knew about them). The main advantage of a hybrid hard drive is to increase the overall performance of the system in which they are installed, using only one drive bay (instead of two if you use both an SSD and a regular hard drive). Now there are "hybrid" models of small sizes, for example, with a thickness of only 7 mm (this is exactly the ST500LM000 model from Seagate), which allows you to install such drives in netbooks / ultrabooks.

The principle of operation of SSHD is based on caching the most frequently used data using flash memory, that is, the SSD part of the “hybrid”. Already at the first start of the operating system on a laptop / PC with a “hybrid”, the files that the operating system needs to load are placed in the non-volatile part of the SSHD memory. As a result, the startup speed of the OS increases, and quite significantly.

The hybrid drive, by the way, shows almost the same file transfer speed results compared to conventional hard drives. But the difference in the operation of different types of devices becomes very noticeable if we compare the access time to files (Access Time). For example, if you take a 500 GB Seagate ST500LT032 drive and compare it with a ST500LM000 "hybrid" of the same capacity, then the file access speed will be 24.2 and 0.3 ms.

As for the speed limit of the interface, the difference is not several times, but 15%. In the first case, 101 MB / s, in the second - 115 MB / s.

There are also disadvantages, and first of all, this is the inability to fit all critical data on the SSD part of the SSHD drive. Usually, an SSD in a “hybrid” is installed with a capacity of 8 GB, sometimes more (for example, models with 32 GB of flash memory are not uncommon), but then such a drive will be more expensive.

At the price of "hybrids" only slightly higher than the price of conventional hard drives. If we take the models already mentioned above, then the price of the Seagate Laptop Thin SSHD ST500LM000 is $73-75, and the Seagate ST500LT032 is about $50.

So, if you want to increase the speed of loading the OS, as well as the overall performance of your laptop / desktop PC, we recommend using "hybrids". Well, that's in case savings are important to you. If not, then you should use SSD and regular hard drives separately.

An article about the advantages and disadvantages of hybrid hard drives that combine the strengths of HDD and SSD drives

Over the past ten years or so, solid state drives (SSDs) have gained popularity in the IT world. First, they have infiltrated laptops and mobile devices with their small form factor and lack of moving parts. Now they are making their way into enterprise storage systems. Using the same flash memory found in USB drives, mobile phones and SD cards, they offer a long list of advantages over their electromechanical counterparts, solid state hard drives. SSD drives for computers have no moving parts, they are more resistant to shock and other forms of physical damage, and they are lightning fast in their read and write speeds.

HDD storage capacities have grown quite consistently - currently, massive 3TB and 4TB drives are in the availability zone, and even the 8TB and 10TB giants have made their way into the market. Hard drives pick up speed up to 15,000 rpm. They are noisier, hotter, and require more power than their flash counterparts.

So why can't we drop our hard drives and solid state drives? The answer is simple: the cost of one gigabyte of an SSD drive is noticeably more expensive. As of January 2015, a 1TB hard drive can cost around $50 and the equivalent SSD costs around $380-$400.

In 2010, a number of manufacturers, starting with Seagate and Samsung, began introducing a third option in the drive world in an attempt to bridge the price and performance gap between HDDs and SSDs by offering a hybrid option. Since then, Western Digital and Toshiba have also started making hybrid drives. The hybrid drive provides some of the best features of both technologies by combining the speed of an SSD with the cost-effectiveness of an electromechanical HDD.

How a hybrid computer hard drive works

The basis of a hybrid hard drive is the combination of a cache with rotating electromagnetic platters of a solid state HDD. Solid State Hybrid Drive (SSHD) typically consists of 8GB, 16GB, or 32GB of flash storage and a larger HDD to store some of the data. The idea is that "hot data" should be available quickly or frequently (eg by the operating system). This data can be cached on the SSD and as a result is retrieved faster than if it were stored on the platters themselves. It's the same principle as installing a hard drive and an SSD on a desktop machine, that is, a dual drive and a hybrid solution, except that the performance optimization is built into the firmware and adapts to storage needs. These adaptive or self-learning optimization techniques eliminate the need to manually move files/applications to their respective hard drives.

There are currently two modes of operation for all hybrid hard drives, or SSHDs. First, the actual optimized mode, or standalone mode, which determines hot and cold data to be written to disk. For the host machine, the drive is no different than the traditional internal storage device.

The other SSHD mode is host optimized mode, or host sticky mode. In this format, the machine host designates which data is hot and cold through its operating system, device drivers, and in some cases, through software. The host machine regularly sends designations to the drive via the SATA interface and instructs the drive how to store the data.

Benefits of hybrid disk storage

The key benefit of using a hybrid storage device is increased performance with high storage headroom without significant cost increases (about $100 for 1TB SSHD) while maintaining high potential. SSHDs have the capacity of a computer hard drive with increased seek speed for cached data on an HDD - and not as expensive as an SSD.

In addition, the hybrid hard drive provides the computer with faster access to critical data, and there are other benefits associated with flash memory, also used on SSHDs. For example, if the calibration is done correctly, you can reduce stress and wear on the drive resulting in longer life than traditional solid state hard drives.

Disadvantages of hybrid hard drives

While hybrid drives are great, they are not perfect. Retrieving data from a hard drive is as fast as a traditional solid state HDD. Hybrid drives are still vulnerable to physical damage, and you won't benefit from the silence on an SSD.

Since we are experts in data recovery, we should discuss the implications of data recovery with hybrid storage. The good news is that the solid-state part of the SSHD is used primarily as a cache or for storing operating system files, and you are unlikely to lose data in that part of the drive. If you manage to lose data from the solid state area of ​​the hybrid drive, recovery presents its own challenges, such as alternative data organization methods.

All in all, hybrid drives have a lot to offer both consumers and business users looking for the speed of an SSD while looking for value per gigabyte of hard drive. This is a great way to bridge the gap between a solid state HDD and a fast SSD.