Today there are a large number various types devices for recording, storing and processing information. One of the most popular developments, which has already become quite a part of our lives, is a hybrid SSHD device.
It is a regular hard drive equipped with a solid-state memory section. Operating principle of this device peculiar.
Story
The device of this type appeared relatively long ago, almost immediately after various types of solid-state drives such as SSDs were put into mass production. The latter had extremely high productivity and other advantages. But they were also distinguished by their almost exorbitant cost relative to ordinary hard drives.
Photo: The world's first transparent SSD drive
The way out of this situation was a hybrid hard drive. It, unlike its more simply designed counterparts, is equipped not only with ordinary pancakes rotating on a special spindle, but also with a memory chip.
So peculiar engineering solution– combine two various types memory in one case - made it possible to reduce the cost of computers and at the same time increase their performance.
In order to understand what an SSHD is, you need to familiarize yourself with its structure. The most important difference from a regular hard drive is the presence of memory chips.
Device
The type of device under consideration for storing and processing data consists of two main parts:
Solid state memory;
Hard drives.
Hard drives can be made of aluminum or glass plates coated with some ferrimagnetic material. Solid-state memory is a microcircuit; data is written to it non-mechanically.
The plates, rotating on a special spindle, are placed in a hermetically sealed chamber filled with nitrogen or other similar gas. It is cleared of foreign impurities, its humidity is minimal. There is a double cleaning system in case dust or other foreign particles get into the containment area. Inside the case there is a three-phase synchronous motor, as well as heads for reading and writing data.
Principle of operation
The operating principle of an SSHD device is very simple. Arrays for recording data are ordinary metal disks with a special coating. Information is recorded on them using the tunnel magnetoresistive effect. As a result of this effect, the magnetic field affects the resistance of the magnetic surface of the disks. Which leads to a change in the magnetization vector of individual elements.
Data is read in the same way. The head hovers above the metal surface and occurs reverse process– the surface resistance of the plates affects the magnetic field of the write head. The information received is analyzed and decrypted.
The operating principle of a hybrid drive is completely different from a conventional one. hard drive. In fact, this chip is a flash memory into which various types of data are written. Its operating speed is much higher than that of a standard hard drive.
The essence of the hybrid SSHD is that metal plates are used to house permanently stored information. The use of the solid-state part of the device is carried out only after starting the operating system. Those files that the system accesses constantly are written to it. Thus, access to them is greatly simplified and accelerated.
It is due to this that the speed of work increases. The connection interface uses an interface called SATA.
Performance
If you compare the file transfer speed of a conventional drive and a hybrid drive, it will be almost the same. In SSHD it will not be much faster; the speed increase due to solid-state memory will be a maximum of 15%. But the difference becomes very noticeable if you measure the speed of file access. This parameter is designated as Access Time in all testing applications.
For comparison, you can use the two most common models:
The data access speed when using ST500LT will be 24.2 m/s. The ST500LM has a similar characteristic of 0.3 m/s. So the performance difference is very large.
The most obvious way to see the difference in performance is when testing in some specialized work. For example, in PCMark 05.
Where is the best place to use an SSHD drive?
The drives in question are used both in laptops and in regular desktop computers. That is why both a full-size version – 3.5 inches – and a smaller one are produced. There are also a large number of models, the thickness of which is within 7 mm. That's why they are often used in laptops.
Most often, drives with solid-state additional memory are used in laptops, since these devices suffer from a lack of performance. This is due to the compactness of the hardware. AND solid state drive allows you to compensate this disadvantage. But you can also often find the disk in question in regular desktop PCs.
Short review
Most often on sale you can find a model labeled as Seagate Laptop Thin SSHD. You can also easily find his review at appearance you can confuse it with the most ordinary disk drive, equipped with two metal plates coated with ferromagnetic coating.
The model under consideration has dimensions 2.5 inches. The data exchange process is carried out through an interface labeled SATA 6. Volume internal memory is 500 GB. The spindle rotation speed is not very high - only 5400 rpm.
Other performance characteristics are also outstanding:
- power consumption – 0.9 W;
- noise level – 2.2 dB;
- impact resistance – 350/1000 g;
- dimensions:
- length – 100.35 mm;
- height – 70.1 mm;
- depth – 7 mm;
- weight – 95 g.
Will be implemented soon full transition on hybrid and solid-state storage devices. Since this direction has very great potential for development.
Extremely high operating speed allows you to carry out a greater number of operations in the shortest period of time. Solid State Read-Only Memory – big step into a new future.
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 those data that are most likely will be required by the user or the 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. On this moment the price for this model is comparable to prices hard drives other manufacturers.
Hybrid drives are a successful technology that allows you to combine the best SSD quality and HDD. Now it is available for desktop PCs, and there is no doubt that other manufacturers will follow Seagate's example.
Test results
| Program | parameter | SSHD read/write | HDD read/write |
|---|---|---|---|
| PC Mark 7 | points | 3618 | 2930 |
| AS SSD Benchmark | points | 40 | 32 |
| Anvil's Storage Utilities | points | 174/145 | 162/102 |
| AS SSD Benchmark | access time, ms | 14,4/9 | 16/12,4 |
| HD Tune Pro | access time, ms | 14,1/9,2 | 15,8/12,5 |
| Lometer | access time, ms | 19/10 | 21/13 |
| HD Tune Pro | speed, MB/s | 172/165 | 162/155 |
| ATTO Disk Benchmark | MB/s speed | 180/158 | 170/155 |
Hybrid drives SSHD - what kind of bird?
- King Servers Blog
In our work we often have to deal with a variety of information storage devices, including hard drives and solid-state storage devices. At the same time, sometimes you come across quite unusual devices that are not common everywhere. For example, SSHD - hybrid hard drives. There are probably people on Habré who are well acquainted with this type of information storage device, but there are also those who have not even heard of such “hybrids”.
So, hybrid hard drives, first of all, are a compromise solution that allows you to both increase the overall performance of the system in which they are installed and reduce the price of such a system.
After all, despite their widespread use, solid-state drives are still quite expensive, and it is unlikely that there will come a time soon when the price of such drives will drop significantly.
Regular hard disks- inexpensive, for the most part, but their productivity is limited, you cannot “jump” above a certain limit. That's why hybrid hard drives appeared. SSHD appeared a few years ago, and at first they were pure exoticism, which few people took seriously (and few knew about them). The main advantage of a hybrid hard drive is that it increases the overall performance of the system in which they are installed, using only one drive bay (rather than two, if you use both an SSD and a regular hard drive). Now there are “hybrid” models small sizes, for example, with a thickness of only 7 mm (this is exactly what the ST500LM000 model from Seagate is), which allows you to install such drives in netbooks/ultrabooks.
The operating principle 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 are needed are placed in the non-volatile part of the SSHD memory operating system For loading. As a result, the OS startup speed increases, and quite significantly.
The hybrid drive, by the way, shows almost similar file transfer speed results compared to conventional hard drives. But the difference is in the work different types devices becomes very noticeable when comparing file access time (Access Time). For example, if you take a Seagate ST500LT032 drive with a capacity of 500 GB and compare it with the “hybrid” ST500LM000 of the same capacity, then the file access speed will be 24.2 and 0.3 ms.
As for the maximum speed of the interface, the difference is no longer 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, it is the inability to fit all critical data on the SSD part of an SSHD disk. Typically, 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.
The price of “hybrids” is only slightly higher than that 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 OS loading speed, as well as the overall performance of your laptop/desktop PC, we recommend using “hybrids”. Well, that's if saving money is important to you. If not, then you should use SSD and regular hard drives separately.
Many have already heard about the new hybrid rigid discs, but most will wonder if they are worth buying? Or maybe, instead of hybrids, it’s better to take a small SSD drive (or a large one, there’s a lot of money), install the 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 in the laptop for a separate SSD drive, so you can only plug one device into it. I settled on a Seagate ST1000LM014-1EJ164 hybrid hard drive with a capacity of 1 TB, and an SSD cache of approximately 8 GB. This is certainly not as much as we would like, but it’s better than nothing at all. This hybrid drive cost me almost 7,000 rubles.
The hybrid disk cache is entirely hardware and there are no programs to configure or optimize it. Programs and files that are frequently used, including system files, are cached.
Pros 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 system loads 25-30 percent faster,
- applications that we often use launch several times faster,
- copying files up to 500 MB, even within different logical drives, occurs at high speed, equal to approximately 200-300 MB/sec (I think the file is first copied to the cache, and then transferred to the hard drive during idle time),
- the whole machine works faster and there are fewer bottlenecks.
Cons of a hybrid drive
Let us note some disadvantages, but they are not critical:
- the cost is almost 2 times more than a regular hard drive,
- low SSD cache volume (in general, there are all sorts of disks, they have 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 operating conditions for the computer.
I think it’s worth buying them only for laptops when it is not possible to install a second separate drive in it. If you have desktop computer, and there is space in it (usually there is always one), then it would be best to take a separate SSD drive, with a capacity 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.
A solid-state drive is an excellent thing in all respects, except for one thing - price.
It often happens that after purchasing a laptop, the owner thinks about an upgrade - he wants the machine to work faster. One of the bottlenecks is the speed of the drive. It would seem that the conclusion suggests itself - install an SSD and rejoice. But what about the accumulated data? Should I also buy a portable hard drive? Throwing away optical drive and shamanize the hard drive bay instead? All options are possible, each with its own inconveniences. But! There is another option that is not often mentioned - installing a hybrid drive - the price of hybrid drives is a little more expensive than regular drives, but their capacity is rather large, and the speed (as they say) is comparable to an SSD.
A beautiful representative of the hybrid family fell into my hands Seagate SSHD, capacity 1000GB (model ST1000LM014, there is also a thin version with a capacity of 500GB). Let's see how justified this upgrade option is.
0. Characteristics
For the curious, I hasten to immediately inform you of the characteristics of hybrid drives:
The test drive has 8GB of solid-state NAND memory and 64MB of cache.
Information is stored on two plates, respectively, 4 heads are used.
Thickness is standard for regular laptops, 9.5mm. For ultrabooks, a thin model with a capacity of 500GB is useful.
1. Appearance.
Supplied in a modest package, the hard drive looks no different from conventional drives.
Only the inscription SSHD can suggest an unusual device. 
The microcircuits on the control board face the body, which provides some protection from external influences. The control board is easily removed, on it we see a Seagate LSI control controller, a 64MB cache memory chip from Samsung, as well as an 8GB solid-state chip located next to the eASIC controller, which is responsible for working with the SSD department. 
It's that simple: take a tricky controller, a piece of a solid-state drive and voila - the hybrid is ready!
2. Testing
I decided to check the operation of the drive in comparison with two obvious alternatives:- a regular laptop hard drive with a capacity of 500GB
- OCZ Vertex 3 solid-state drive, 60 GB capacity
Let me remind you that a larger SSD will work faster than in the tests I presented.
I also note that the price of a 120GB SSD is on average comparable to the price of a 1TB SSHD.
Testing was carried out in two stages:
1. synthetic tests of read/write speed and access time
2. Hard drives with the cloned OS were installed one by one in the laptop, and the startup time of the OS and programs was measured.
It seemed to me that a simple set of synthetic tests was not enough, since to optimize the operation of the solid-state cache in Seagate drives, Adaptive Memory technology is used (I suspect that the tricky eASIC controller is responsible for its implementation). The essence of the technology is that the most frequently used data is cached on the SSD and access to it subsequently accelerates. You can read more about this technology on the Seagate website
Simple tests do not use any data, but simply check physical properties write/read, i.e. all the cunning mechanisms remain unused and are unlikely to bring tangible gains in terms of performance.
Therefore, it is the time indicators of application launches that seem to me to be the most objective.
So what happened...
2.1 Synthetic tests
Crystal Disk Mark
as ssd benchmark
Atto disk benchmark
Speed tests: CrystalDiskMark, Atto disk benchmark, as ssd benchmark give approximately the same picture
It is not surprising that the undisputed leader is the SSD, while the SSHD and HDD show approximately equal results in sequential read/write, but in tests of random read/write speed of small blocks, the SSHD shows a better result, although compared to the results of the SSD this advantage does not seem to be significant.
PCMark 7
The PCMark7 test, when testing hard drives, acts a little smarter and checks not only the write/read speed, but also the capabilities of real operation, simulating the operation of real applications.
The undisputed leader remains the SSD, but the advantage of a hybrid drive suddenly becomes very noticeable. When it comes to launching and running applications, the SSHD performs excellently, far outperforming a traditional drive.
2.2 Launching applications
The startup time of the OS (from the POST screen to the launch of the Calculator program in startup) and programs was measured using a stopwatch. The measurements were carried out 5 times, the result is the arithmetic mean.
In real work, the hybrid drive performs excellently. I will also note that the final diagram does not quite objectively describe the operation of the SSHD, since due to the adaptive memory mechanism, the startup time decreases each time until it reaches the optimal mode. So, the first OS restart took 107 seconds, while the fifth measurement showed 58 seconds. The final boot time reached a stable 36 seconds, which in practice is not very different from the readings of the solid-state drive.
The loading speed of applications is also indicative.
3. Summary
To summarize, I would like to describe my impressions. When I first tried to work on a PC with an SSD, I was impressed by the speed of operation, launching applications, and the overall responsiveness of the system. After this experience, working with HDD-based systems is a real pain, the OS takes an unbearably long time to load, the system seems thoughtful and unresponsive. Based on the results of working with the hybrid drive, it became clear that this real alternative SSD. The system, of course, is a little less responsive, but in general there is no such agony as with an HDD. The advantage of this compromise solution is the low price per GB of volume (compared to SSD), since for the same money you can buy, for example, either a 120GB SSD or 8 times more voluminous, 1TB SSHDThus, the hybrid absorbed both best benefits both types, and generally insignificant disadvantages
High operating speed (compared to traditional drives)
+ Low price (compared to solid-state drives)
Operating speed is slower than SSD
- The mechanics are in place - the pancakes are spinning, the heads are scouring.
Conclusion: A hybrid drive is an excellent compromise solution for a home laptop.
Loading...
