What is an SSHD drive? Why is a hybrid drive better than HDD and SSD? The best hybrid hard drives

The first qualitative leap in the field of data storage in personal computers occurred about 30 years ago - when the hard drive became the main storage device. The personal computer equipped with the latter really reached a different level compared to its predecessors, equipped only with floppy drives, or even working with household tape recorders, and in all respects. Simply because the high capacity and speed of hard drives led to a sharp increase in power application programs, and indeed to a completely different scenario for using technology. Actually, that's why this scheme quickly became standard and remained unchanged for many years.

However, by now the market has begun to undergo further developments. Hard drives continue to be the main type of drive in mass-market computers. However, it is no longer the only one - flash memory is nipping at its heels. However, solid-state drives still cannot compete with hard drives in terms of capacity, but the trick is that the user often does not need high capacity. In any case, it is not needed in every computer - now a personal computer is not the only device of this kind at the owner’s disposal, but just part of a global infrastructure that includes both local NAS and global cloud services. Accordingly, parameters such as performance or resistance to external adverse influences (shaking, for example) are taking the lead in many areas of use, but here flash memory-based drives are head and shoulders above their mechanical relatives.

But in practice, everything is even more complicated than the head-on confrontation between mechanics and semiconductors. The fact is that manufacturers have long been working on hybrid drives that include both. In terms of capacity, they do not lag behind hard drives (which is not surprising, since the hard drive is the basis of all hybrids), but at the same time they inherit many of their shortcomings, and performance... It’s more complicated with it. A conservative estimate (with which we tend to agree) is that the performance of hybrids is no lower than that of hard drives, and in a number of use cases can be comparable to solid-state devices. But not always, i.e. everything is simple only at the extreme points: hard drives are slow, SSDs are fast. And hybrids - depending on your luck.

However, such a vague definition certainly does not suit everyone. The only problem is that accurate testing of systems with hybrid drives is extremely difficult due to the variability of the results. Depending on the chosen scenario and test programs, it is not so difficult to obtain both performance levels at the level of conventional hard drives and comparable to solid-state drives. Moreover, the more low-level test programs we take, the more results of the first type we get. And high-level tests of the entire system usually do not depend too much on the performance of the drives themselves, so in them you can easily achieve parity between all types of the latter.

But no matter how difficult the search for an exact answer to the question posed may be, it needs to be done. Including using different approaches. In the line of articles devoted to testing drives themselves, we mainly focus on low-level tests and try (for obvious reasons) not to compare devices of different types with each other. Today's material is of a different kind. In it we will limit ourselves to high-level benchmarks, but we will test five different drives within one system. Let's see what comes out of this.

What and how we test

Not long ago we got our hands on gaming laptop MSI GP60, which differs from most devices on the market in the use of a hybrid hard drive Western Digital. This is already interesting in itself, since, unlike Seagate, which sells its hybrids left and right through all channels (so anyone can buy them), WDC so far ships its drives of this class only to manufacturers of finished systems. According to the company, this should help the fullest and correct use of the potential of hybrid hard drives and avoid their “incorrect” use. For example, an individual buyer can try to install a couple of hybrids in RAID0, which is not very reasonable (mostly sequential operations are accelerated, but the same level of performance can be achieved on a cheaper array of conventional hard drives), or use additional external flash caching, which in most cases it will only worsen the performance. And the laptop manufacturer definitely won’t do anything stupid :) Moreover, if possible, he will configure the system accordingly and include the “correct” utilities in the kit (ideally). In general, this is an approach with its pros and cons. And its main disadvantages on the part of testers (i.e. us) is that you can’t just go to the store and pick up one hard drive - you need to get a whole system with it somewhere. However, as we see, it is not so difficult :)

So, the WDC WD10J13T itself is interesting in itself. Despite belonging to the Black series, it has a platter rotation speed of only 5400 rpm, which, in general, is already becoming common: 7200 laptop hard drives are dying out, since hybridization is now becoming the main method of increasing productivity. This model also has as much as 24 GB of flash memory installed, which is not so bad - SanDisk caching SSDs, actively used by many laptop manufacturers, have just such a capacity. And the pancake package is also familiar - two 500 GB disks, which is currently the maximum for 9.5 mm WD hard drives. Note - only 5400 models: “black” at 7200 rpm. has not been updated for a very long time and uses less dense platters, so the capacity is limited to 750 GB, and with some types of load it is narrower and the higher rotation speed of the platters does not help it break away from the cheaper “blue” models (and, accordingly, older hybrids) . In general, this is a capacious hard drive, accelerated by hybridization.

Who can compare it with? Of course, testing would not be complete without the Seagate SSHD. Closest to technical specifications is ST1000LX003: also a terabyte on two plates and 32 GB of flash memory, but, unfortunately, we have not tested it yet. But I found the Laptop Thin SSHD ST500LM000 “at hand”. The plate in it is the same as in older models, but there is only one. However, in comparison with an SSD, its 500 GB capacity still looks good - flash memory of this or greater capacity is still too expensive from the point of view of many buyers. So the main drawback of this model’s performance characteristics is only 8 GB of flash buffer, which, as we already found when testing the drive, is not enough. On the other hand, the technology developed over several years may well compensate for the advantage of a Western Digital drive in flash capacity, so the comparison promises to be interesting.

But, be that as it may, the question is “which hybrid to buy?” Users ask themselves much less often than “is it worth buying a hybrid hard drive?” (especially since, as mentioned above, Western Digital does not yet sell its models at retail, which further narrows the possibility of choice as such). That is why it is impossible to avoid comparison with “ordinary powder,” i.e., a simple hard drive. So as not to offend any of the manufacturers, an example of such today will be the Hitachi Travelstar Z5K500-320: a single-platter from a “neutral manufacturer” with the same rotation speed of 5400 rpm as both test subjects. Of course, there are faster “classic” hard drives, but the modern “floor” is more important to us, not the “ceiling”. And in general - as has been said more than once, the latter is already beginning to slowly disappear: the role of top models is beginning to be played by hybrids, and devices with a rotation speed of 7200 rpm. become a dead-end branch of evolution.

And finally, the favorites today- solid state drives. There will be two of them - the budget Crucial M500 120 GB and the Samsung 840 EVO 250 GB belonging to a slightly higher class. Note that the “budget” of the M500 is, in general, also relative - in price it is approximately equal to a terabyte hybrid from Seagate with 8 GB of flash memory (there are no retail prices for the WD10J13T yet, but it is unlikely that the cost of two similar drives from different companies can be too much vary). Actually, this is the answer to the question - why solid-state drives are still unable to displace mechanical drives: the prices are too different. Yes, of course, it is now possible to purchase an SSD at the price of an HDD (especially an SSHD), but the capacity will differ radically - eight times, i.e. almost an order of magnitude. A quarter of a terabyte of flash is relatively more profitable than an eighth of flash, but here it’s better not to compare absolute prices with hard drives. And if the buyer needs half a terabyte, then he will either have to buy an SSD at the price of a budget (even not the cheapest) laptop, or... Or give up on all the theoretical advantages of new technologies and turn to time-tested ones. Or also new, but less radical, i.e., hybrid drives.

As for the tools, there is no particular point in leaning on low-level tests - we have already established that. But PCMark is suitable as a measuring tool. Moreover, the two latest (at the moment) versions of this test package are also used when testing laptops, so some of the results have already been obtained earlier.

Low level - technology matters

So, let's start with the routes specialized for storage devices. There are too many detailed results, so we will limit ourselves to general estimates.

There are two suitable traces in PCMark7, so let's start with the more “refined” one. As you can see, hybridize does not hybridize, and solid-state drives are out of reach. They themselves can vary greatly in speed, but a budget SSD is already a couple of times faster than the fastest of the three hard drives participating in testing. However, flash buffering is not so bad - it allows you to increase performance on this route by 30-50%, but this is not at all enough to cross the chasm separating “mechanical” drives from semiconductor drives.

If you rise to a higher level and get closer to real loads, then the situation no longer looks so clear. Yes, of course, SSDs are still out of reach, but their advantage is greatly reduced compared to the previous case. That is, we can talk about a twofold difference only when comparing a slow hard drive with fast SSD, and hybrid drives can already somehow be compared with budget solid-state ones. Of course, we are still not talking about equality, but a lag of some 20% against the background of many times greater capacity at similar prices is something that many users can already accept.

In PCMark8, this group of tests turned out to be completely new, and not a significantly reworked old one. The result is at least interesting - the difference between different hard drives or between different SSDs. The former are about one and a half times faster than the latter, but within the groups the spread is not too great.

So, let's drop everything, break out the piggy bank and run to the store? Take your time - these are just relatively low-level tests.

PCMark7 - Ubiquitous Storage

As we already wrote in the review of the laptop itself, with the exception of the Computation test, in each PCMark 7 scenario there are tasks to determine the performance of the data storage subsystem. Moreover, when calculating the integral result, the weight of these results turns out to be quite large. What should we get as a result?

Computation, of course, is practically independent of the type or specific model system storage. The influence of the latter can be traced a little, of course, but the difference (albeit stable - easily repeatable) is somewhere within the measurement error.

The transition to other routes changes things dramatically. Lightweight (light, non-stressful computer work) is almost identical to System storage. Relatively, but not absolutely, of course: after all, the test also contains a considerable number of tasks for other computer systems. As a result, we can talk about something like parity between hybrid hard drives and budget SSDs - the difference between them is only about 10%, which is not important for many users. At the same time, “traditional” hard drives are significantly slower, but top-end SSDs are much faster.

The Productivity test is also very “easy”, and it includes only two traces from the System storage group, and not three as in the previous case. True, here is one of them (namely launching applications), as we have seen more than once when testing drives, O and everyone else. In general, the results are already familiar: a computer with a traditional hard drive is almost two times slower than one equipped with a fast SSD, but budget models of solid-state drives and hybrid hard drives are somewhere in the middle between them, and provide comparable performance. But even that is not the same. True, their capacity is even more unequal :)

There is more work in Creativity, so the difference between drives different types begins to shrink, even if it does not disappear altogether. But don’t be surprised that many may not notice it. That is, a person exchanges a hard drive for an SSD to work with videos and photos in anticipation Wow!, but instead of “wow” he gets 20% of the productivity, and not everywhere. Also a lot, of course, but knowing the numbers in advance, there would be even fewer people willing to pay for them.

And finally, the entertainment group. There are only two “accumulative” tests here (and one of the traces is not very accelerated on an SSD), and there are 11 others. Some of them, however, flash memory allows you to pass faster, but not all of them are significant. As a result, we come to the conclusion that for “home entertainment” use of a computer, the type of drive used is not very important. Hybrid hard drives certainly provide some performance gains, and solid-state ones are even faster, but the difference is not as dramatic as the low-level tests might lead you to believe. Which is quite consistent with everyday logic - a fast drive will allow you to launch the game faster and/or load new levels, but the frame rate in it will be determined by the video card (and a little by the processor, memory, etc.), regardless of where the game is installed. On the other hand... It is precisely in order to remove these most annoying delays when switching between levels that gamers buy SSDs. And those who are not too irritated by them (at least, not enough to part with a significant amount of money) do not buy.

The overall PCMark7 result, as one would expect, is even more dependent on the performance of the drive used than individual traces. But this still doesn’t give us anything new - a familiar situation, where mechanical drives are obvious outsiders, fast solid-state drives are the undisputed leaders, and somewhere between them is the habitat of budget SSDs and hybrid hard drives, which can, to a first approximation, be considered equal to each other.

PCMark8 - everything is calm in Baghdad

The operating logic of the new Futuremark test package has changed greatly - unlike its predecessor, it does not try to “mix” cumulative tests, focusing specifically on “real software” (which in some scenarios may actually be real - as we already wrote, the package is capable of using different versions Adobe Creative Suite or Microsoft Office, for example installed by the user). However, as we have already seen, and, in fact, the Storage group in this package finds fewer differences between drives of different types. Let's see how all this affects high-level tests.

Home computer - All Colas are the same. In any case, when running tests repeatedly, only “pure” mechanics lose (and only 10%), and hybrid hard drives are able to quickly cache the bulk of the work, which makes them equal to SSDs. But even if we plan for the worst case scenario (which, unfortunately, is almost impossible to simulate in this version of the package), we will “fall” only to the level of ordinary hard drives. That is, with this use of the computer, as we see, there is no need to chase an SSD (in any case).

What is noteworthy is that in an even easier “working” scenario, the gap between solid-state and hybrid drives from traditional ones only increased, while they themselves remained approximately equal to each other.

If content is not only consumed, but also produced, the use of flash memory in any form becomes even more preferable. In itself, there is no longer any need to chase top-end solid-state drives, since budget models of the latter, as well as hybrid hard drives, provide a level of performance comparable to them. However, you can look at the situation from the other side - in fact, here the difference between the two hybrids that took part in testing is comparable to the difference between drives of different classes.

And sometimes it can even exceed it. In fact, the Seagate Laptop Thin SSHD lags behind the younger modification of the Crucial M500 less than it is ahead of the hybrid WD Black. However, here the fastest SSD taken outperforms the slow “classic” hard drive by less than 15%. But it overtakes, i.e. the already established dependencies are in force.

Perhaps the most difficult work scenario also turned out to be the most loyal to solid-state drives. So we come to the conclusion that to use Adobe products, purchasing an SSD is highly desirable. Which is not surprising - applications from this manufacturer work very actively with hard drives. Especially the same Photoshop, which is actively creating a large number of temporary files. Hybrid hard drives are unable to greatly speed up the process - after all, the mechanics prevent you from achieving high performance. But the potential of solid-state drives is fully utilized. A “smart” SSD allows you to get a one and a half times increase in performance relative to hard drives, which is very noticeable in the same environment. Especially in laptop computers, where, for example, it is impossible to obtain a similar increase due to the processor in some cases - let us recall that the system we used had a Core i7-4700QM installed: albeit not the highest in model range, but quad-core Haswell, which lags behind the extreme model of its generation by only 20 percent (the competition with representatives of older lines is even less clear). But, of course, to get such an effect, the solid-state drive must be used not only for installing programs, but also for working with data - otherwise the increase will be much more modest. And this unambiguously addresses us to capacious models of the top lines (the rest may simply not fit everything you need), which themselves can cost as much as a middle-class laptop. Thus, hybrid technologies are even more relevant - as we see, such hard drives are quite capable of competing with some budget SSDs, offering the buyer many times more working space, which can turn out to be extremely important (“splashing” a hundred gigabytes of photos with a modern DSLR is a simple matter and within one trip). In general, based on a combination of factors (speed, capacity, price), there are no clear leaders and clear outsiders. This means that all technologies and their combinations will remain relevant in the near future. Each one is simply in its place.

Total

Manufacturers of solid-state drives “love” to use the results of low-level benchmarks in advertising, and when promoting hybrid ones, the main emphasis is on the fact that sometimes they are almost as good as solid-state drives. Both are true. But not all of them :) In the first case, do not forget that low-level “parrots” are extremely rarely achievable in practice - more often than not, the performance of the entire computer when solving certain problems is “limited” by the characteristics of completely different components. Or even nothing at all except the user. As you might guess, this is often the “stumbling block” for hybrids: there are many loads where “regular” hard drives are often not too far behind solid-state drives even without any hybridization. Therefore, you should not count on the fact that SSD installation Instead of even the slowest hard drive, adding it to any laptop will radically speed it up everywhere - this may not affect the time it takes to complete practical tasks at all, i.e., you will continue to process the photo for 15 minutes. Another question is that the comfort of this event may increase - in particular, delays when launching programs will no longer be noticeable. Or “brakes” when loading levels in a game, etc. But the frame rate, as we wrote above, will not increase - it all depends on the video card and, to a lesser extent, on the processor. To view a photo in RAW format, it seems that you need to quickly read it from the media. However, when high resolution“developing” RAW itself can take several seconds (or even tens of seconds) - against this background, the time for reading a file even from a USB flash drive will simply be “lost.”

For many users, solid-state drives are quite expensive, and conventional HDDs are not powerful enough. In this case, hybrid drives - the so-called SSHD (Solid State Hybrid Drive) - can become a compromise. They are a combination of low-cost drives on magnetic disks, several gigabytes of flash memory based on NAND cells and an intelligent SSD controller. The latter stores frequently used data - for example, OS system files and program files to fast flash memory, and rarely used ones, such as photos or music, to a magnetic disk. For optimal performance, SSHD requires certain time for training, during which it remembers calls to frequently used data. As a result, when booting, the PC can access the flash drive even before the HDD starts working, which can significantly reduce startup time.

SSHDs are now available in all common form factors. In almost all respects, combined drives are ahead of standard HDDs. Immediately after installation, but before creating the optimized area in flash memory, hybrid drive demonstrates significantly higher operating speed. After several reboots, the gap increases. In some conditions, SSHD can even be faster than SSD.

Hybrid HDD - this is the high speed of an SSD drive combined with the large capacity and low cost of a conventional HDD. Working with a fast solid-state drive (SSD) is complete comfort: the PC boots in just 10-15 seconds, programs launch very quickly, and data recording does not affect the speed of other processes. But despite the fast data transfer, they do not allow large collections of movies, photos and music to be stored on disks. To combine high speed and large volume, you can use combined solutions that work as a duo: a classic HDD and a solid-state drive.
In this tandem, an SSD drive is used as an intermediate storage device (storing frequently used files), while a classic hard drive is used for long-term storage of information. What information should be included in SSD drive defines the integrated controller by identifying the data type most commonly used during system operation. There are certain limitations: the size of the solid state drive is sufficient for system files and small documents, of course it is not enough for multimedia and it will not be possible to enlarge it.

SSHD Advantage

Some SSHD models can “sag” to the level of conventional HDDs when writing data. This suggests that the disk controller is using almost all flash memory to optimize read operations. Compared to a standard hard drive, a hybrid drive significantly increases the speed of a laptop, but it cannot stand comparison with an SSD. The main advantage of SSHDs is the price: despite significantly higher performance, they cost almost the same as HDDs.

Hybrid Drive Performance

Hybrid drives operate at SSD speed only if they can properly organize intermediate storage of information. Unfortunately, they do not always succeed in this. In terms of performance, such media are very close to a full-fledged SSD, since in practice the operating system starts from hybrid disks almost 15-20 seconds faster than from classic HDDs, and the performance when checking a computer for viruses is far from being on par with solid-state disks not all, Hitachi HGST Z5K320 and Toshiba MQ01ABD100H performed best. Hybrid drives reach maximum performance only after several OS reboots, since the effective operation of the hybrid hard drive possible after a learning process (the hybrid drive must recognize frequently used files).

In this article I will tell you what a hybrid hard drive is, why it is better than the usual HDD, as well as the pros and cons compared to an SSD.

For most ordinary users I will now reveal a big secret - the weakest (read slowest) link in the chain computer system is a hard drive or hard drive. You can have the most fast processor, the best video card and a bunch random access memory, but the slow and, excuse the expression, “dumb” hard drive nullifies all the work of this cool hardware.

This was the case until recently. Now there are SSDs or solid state drives. They helped get rid of this bottleneck in computer performance. Many people use them as their main boot disk for the operating system, which is very justified, but the high price and small amount of memory does not make it possible to use them more widely.

Production hard drives very complicated technological process, since it has many moving parts, which greatly limits the reduction in device size without losing certain characteristics (which is probably why so many modern hard drives fail now). Manufacturers find themselves at a technological impasse. There is no room to further increase the capacity of disks and their density.

To solve this problem, solid-state drives were created, and in 2007, Seagate developed the world's first hybrid hard drive or SSHD (solid-state hard drive). This is a physical data storage device in which data storage technologies of the 60s (hard disk on magnetic disks, HDD) and modern times (SSD drives on) are intertwined.

In general, this looks like an ordinary hard drive with significantly increased flash memory. The first samples had 128MB, but now there are models with 32GB.

The result is a very interesting and practical product. It inherited a large capacity from a regular disk, and a large, one might even say huge, data cache from a solid-state drive.

Speed ​​parameters or HDD and SSD vs SSHD

The process of increasing the speed of the operating system and applications using such hybrid drives is as follows:

After installation operating system on a hybrid hard drive, the first boot will occur at normal speed, but after several reboots, the time will decrease due to the device's microcontroller entering the most frequently used operating system data areas into a large cache. Tests have shown that booting a system with an SSHD is only 5-10% slower than a regular SSD. The same will happen with various applications, games, etc. The main thing is that the disk has enough flash memory for everything you need.

In late 2011 and early 2012, speed tests showed that hybrid SSDs with a 750 GB HDD and 8 GB cache were slower than SSDs in random read/write and sequential read/write, but faster than HDDs when running applications. and turning off.

The amount of cache memory significantly affects the cost of the final product. Therefore, when choosing a drive, you must take into account how resource-intensive applications you are going to run on it and their number.

At the heart of hybrid drive technology is deciding which data elements are prioritized by flash memory and which are not. Therefore, SSHDs can operate in two main modes:

Automatic mode or self-optimized

In this mode, the hybrid hard drive independently makes all decisions related to data distribution and does not depend on the operating system.

Host-Optimized Mode or host-hinted

In this operating mode, the Hybrid SSHD enables the extended SATA "Hybrid Information" command set. Based on these commands, the operating system and device driver, given the structure file system,decides which data elements to place in NAND flash memory.

Some specific features of SSHD, such as host-hinted mode, require software support in the operating system. Support for host-hinted operations appeared only in Windows 8.1, while patches for the Linux kernel have been available since late 2014. They are expected to be included in the Linux kernel in the future.

Historical reference

In 2007, Seagate and Samsung introduced the first hybrid drives: Seagate Momentus PSD and Samsung SpinPoint MH80. Both were 2.5-inch and had 128 MB or 256 MB of flash memory. The products are not widely available.

In May 2010, Seagate introduced a new hybrid product called the Momentus XT drive and used the term " Solid State Hybrid Disk (SSHD). It includes 500 GB of HDD memory with 4 GB of integrated NAND flash memory.

In April 2013, WD introduced 2.5-inch WD Black SSHD drives, including 5 mm thick SSHDs with 500 GB of regular memory and flash memory in sizes of 8 GB, 16 GB and 24 GB.

Pros and cons of hybrid HDDs

The main advantage of a hybrid hard drive is a significant increase in performance disk subsystem, especially in netbooks and laptops, where hard disks less productive and you cannot install a second disk, as in a regular PC. It’s not for nothing that the very first SSHD disks were developed in the 2.5-inch laptop format. Later, 3.5-inch hybrid drives were released. Although now in laptops with a disk drive, it is possible to replace it with a hard drive or solid-state drive, but I will tell you how to do this in one of the following articles.

The disadvantages include the inability to fit all critical data on the flash memory of an SSHD disk. But it also doesn’t make sense to install more than 32GB on a hybrid SSHD, since it will be cheaper to buy a regular 64GB SSD.

At the moment, their price is significantly higher than that of conventional hard drives. For example, at the time of writing, a 1 TB hard drive Seagate Desktop SSHD model ST1000DX001 cost about 6,000 rubles, and its competitor 1Tb Western Digital WD Blue SSHD WD10J31X cost about 5,500 rubles. At the same time, a regular 1 TB Seagate Barracuda ST1000DM003 hard drive will cost you 3,600 rubles. And this includes models with only 8GB of memory. With more quantity the difference will increase. But this is still several times less than the cost of an SSD of similar size.

Conclusion

Hybrid hard drives are a compromise solution that allows you to increase overall performance system in which they are installed and reduce its price.

You could say this is an evolutionary development of conventional HDDs. Due to the increased cache, it was possible to reduce the number of disk accesses, which was reflected in reduced power consumption and heat dissipation, durability and reduced noise during operation. All this makes them much more productive and practical than HDDs, and several times cheaper than SSDs.

The original purpose that the SSHD was supposed to fulfill was to be a low-cost replacement for SSDs and hard drives in laptops and mobile computers completed successfully. After testing the technology and eliminating the shortcomings, manufacturers began to produce 3.5-inch formats for a regular PC.

Thus, for an expensive PC and laptop, it is better to choose a high-speed solid-state drive with a large capacity on which to install the operating system and the programs and applications necessary for work, but for a regular PC and especially a laptop, an SSHD is ideal, which will replace obsolete and slow ones hard disc drive.

There is no doubt that solid-state drives are the future: such drives are significantly superior to classic hard drives in speed, compactness and reliability. However, they are also superior in price, and this is the only thing that prevents them from dominating the market.

Many manufacturers quickly realized that until technologies for the production of solid-state drives became cheaper, they could combine the advantages of flash and mechanical drives in one device to ensure high speed and an affordable price. Such disks are called hybrid.

On hybrid disks, data that needs frequent access is written to flash, and files that are rarely used are stored in the main memory of the HDD. Such technologies are in demand, first of all, in laptops, where there is often simply no room to install both a mechanical hard drive and a solid-state drive.

Seagate considered this situation pure discrimination, and released a model line of Desktop SSHD drives - the first all-hardware hybrids designed specifically for desktop PCs.

We tested the Seagate hybrid drive, made in the 3.5-inch form factor (145x100x26 mm). The main line includes disks with a capacity of 1, 2 or 4 TB, each platter is a terabyte (respectively, up to four platters and two read-write heads for each). Clipboard - 64 MB.

The role of the solid-state cache is performed by a Samsung MLC Flash memory chip, manufactured using a 24 nm process technology, with a Toggle-Mode DDR 1.X interface. Inside the case there are two 64 Gbit NAND devices, which gives throughput interface about 266 MB/s. Spindle speed is 7200 rpm (for 1 TB and 2 TB versions) and 5900 rpm for 4 TB. Disk connection interface - SATA III 6 Gbit/s with NCQ technology. Typical power consumption under load is 6.7 W, and in sleep mode - 0.8 W.

The amount of solid-state memory here is only 8 GB, but even on them we cannot write anything ourselves. Flash recording occurs automatically using a special Adaptive Memory algorithm. It uses fast memory as a kind of cache, transferring the most frequently requested data there.

At any given time, the cache contains only the data that is most likely to be needed by the user or system. For example, if the computer is turned on and off frequently, then space in the semiconductor buffer will be allocated for system files.

If the user often runs a program or game, then the executable file also has a good chance of ending up in cache memory. The same can be said about pictures, electronic documents, videos and so on. Seagate specialists claim that their algorithms are self-learning: the longer the disk is installed on the computer, the faster it works. Write operations are also cached, which significantly speeds up copying.

As they say, everything is learned by comparison. Adaptive Memory technology functions, and quite successfully: an SSHD-type drive is significantly faster in operating speed than a regular HDD. On a computer with such a disk, installation, loading and running of applications and games, loading the operating system and copying data are much faster.

Times Windows boot 7 installed on this disk was halved after several reboots. Impressions from use are supported by test results. We analyzed two 2TB Seagate drives in various synthetic tests: the ST2000DX001 (hybrid) and ST2000DM001 (mechanical), which otherwise have similar characteristics.

When you run the test for the first time, the results obtained are almost identical, but when you run the test 3-5 times, the results improve noticeably. So PC Mark 7, for example, gives a computer with an SSHD 3618 points, and for a computer with an HDD this figure was 2930 points; in the AS SSD Benchmark utility, the tested drive scores 40 points, and its rival - 32.

The results clearly demonstrate the effectiveness of the Adaptive Memory algorithm. The average write and read speed is 160-170 MB/s. At the same time, the CPU load at the time of reading and writing does not exceed 1%. Disk access time is on average less than 15 ms. The performance is, of course, lower than that of a full-fledged solid-state drive, but at the same time, it significantly exceeds the characteristics of conventional HDDs.

The manufacturer did not leave the opportunity to regulate the algorithms for using flash memory. The user cannot forcibly pin any application there, but the smart algorithm is much more convenient and reliable - it will not be left in the cache and forgotten unnecessary files, which will only clutter it and not increase productivity.

The price of a “smart” drive is affordable: 5,000 rubles for a 2 TB drive. We recommend a disk of this volume for purchase: it has high speed rotation and optimal price-capacity combination. At the moment, the price of this model is comparable to the prices of hard drives from other manufacturers.

Hybrid drives are a successful technology that allows you to combine the best qualities of SSD and HDD. Now it is available for desktop PCs, and there is no doubt that other manufacturers will follow Seagate's example.

Test results

SSHD is a new marketing term coined by Seagate employees to refer to drives in the market known as hybrid hard drives, which are a combination of a traditional hard drive (HDD) and new technologies.

Today we will talk about the pros and cons of this type of drive and whether they are worth your attention and, importantly, money.

What is the advantage of SSHD?

Seagate's advertising headlines read: " SSD performance. Hard drive capacity. Affordable price". Essentially what they are trying to say is that SSHD combines the benefits of both technologies without any significant cost. But if this is true, then why hasn't hybrid hard drive technology revolutionized the storage market yet? We’ll talk about this later, but for now let’s try to take a closer look at these “hybrids”.

SSHDs are essentially regular HDDs, but with a compact, small-capacity solid-state drive added to the disk controller and acting as a kind of cache for frequently used files. Therefore, you should not be surprised that the memory capacity of SSHDs is not inferior to classic hard drives.

As for cost, hybrid hard drives cost about 10-20% more than traditional HDDs - this is the result of adding additional cache memory and firmware to manage that cache. On the other hand, they are much cheaper than solid-state drives, many times cheaper.

It all sounds quite cool and optimistic, but...

Is SSHD performance really the same as SSD?

The performance issue of hybrid hard drives directly depends on how the user uses the system, and the limiting factor in that very performance is the small amount of cache memory (currently about 8 GB), which is simply not enough to perform more or less serious tasks.

If the user “uses” his PC to a minimum, well, let’s say, surfs the Internet, sits on social networks, reads email, plays solitaire and plays chess, then such a user will have the greatest benefit from using hybrid hard drives, because in this scenario, the cache memory is quite enough to fully process all data at a speed corresponding to an SSD.

But, if we take into account another user who, let’s say, plays a variety of “heavy” computer games, then we can safely say that this user will not notice any difference in performance if he changes the HDD to an SSHD. Why? Because the cache size is quite small and the files are the same computer game it will be constantly updated and cannot be reused (from the cache), since it will be deleted and replaced with new files. And if the files are not reused, then there will be no real benefit from the SSD cache.

The same applies to copying data. If you copy, say, a folder of files and want to move it from one place to another, and it takes up more than 8 GB, then, accordingly, not the SSHD cache will be used, but its regular memory on a magnetic hard disk, and the copying speed will be the same , just like on a classic HDD.

But, as a “sweetener”, it is worth noting that the system boot when you turn on the computer will be approximately 10 seconds, which practically corresponds to the speed of the SSD.

So who needs an SSHD?

The primary market for solid-state hybrid drives is laptops. The fact is that the limited space of the case does not allow installing more than one disk in these systems. Installing only one SSD can provide greater performance, but limit the amount of data that can be stored on it. On the other hand, installing a single HDD will provide a lot of space, but the hard drive will not perform as well as an SSD.

SSHD, in turn, can offer simple and affordable way provide higher productivity with the same volumes internal memory- an excellent compromise. Plus, since most laptops are used for work rather than gaming, the benefits of SSHD drives become even more attractive.

For desktop systems, however, I do not yet recommend installing hybrid hard drives, since the case personal computer allows you to seamlessly install multiple drives, namely SSD (for system operation) and HDD (for data storage), which will provide excellent performance and a large amount of disk space.

An exception would be mini-desktop systems, which only have internal space for one drive.