ssd read speed. FAQ Battle of HDD and SSD

Test Methodology

Testing is carried out in the Microsoft Windows 10 Enterprise x64 Build 16299 operating system, which correctly recognizes and maintains modern solid state drives. This means that in the process of passing the tests, as in normal everyday use of the SSD, the TRIM command is supported and actively involved. Performance measurement is performed with drives in a "used" state, which is achieved by pre-filling them with data. Before each test, the drives are cleaned and maintained using the TRIM command. Between individual tests, a 15-minute pause is maintained, allotted for the correct development of garbage collection technology. All tests use randomized incompressible data.

The partition within which the speed of operations is tested has a size of 32 GB, and the duration of each test is forty seconds. Such parameters, in particular, will allow you to get more relevant results for those SSDs that use various SLC caching technologies.

Applications and tests used:

• Iometer 1.1.0
  • Measuring the speed of sequential reading and writing data in blocks of 128 KB (the most typical block size for sequential operations in desktop tasks). Testing is carried out at different request queue depths, which makes it possible to evaluate both realistic and peak performance parameters.
  • Measurement of random read and write speed in 4 KB blocks (this block size is used in the vast majority of real operations). The test is carried out twice - without a request queue and with a request queue with a depth of 4 commands (typical for desktop applications that actively work with a forked file system). The data blocks are aligned with the flash memory pages of the drives.
  • Establishing the dependence of random read and write speeds when the drive is working with 4-kilobyte blocks on the depth of the request queue (in the range from one to 32 commands). The data blocks are aligned with the flash memory pages of the drives.
  • Establishing the dependence of random read and write speeds when the drive is working with blocks of different sizes. Blocks from 512 bytes to 256 KB are used. The depth of the request queue during the test is 4 commands. The data blocks are aligned with the flash memory pages of the drives.
  • Measuring performance under a mixed multi-threaded load and establishing its dependence on the ratio between read and write operations. The test is performed twice: for sequential read and write operations in 128 KB blocks, performed in two independent threads, and for random operations with 4 KB blocks, which are performed in four independent threads. In both cases, the ratio between reads and writes varies in 20 percent increments.
  • Investigation of SSD performance degradation when processing a continuous stream of random write operations. Blocks of 4 KB and a queue depth of 32 commands are used. The data blocks are aligned with the flash memory pages of the drives. The duration of the test is two hours, instantaneous speed measurements are taken every second. At the end of the test, the ability of the drive to restore its performance to its original values ​​is additionally checked due to the operation of the garbage collection technology and after the TRIM command has been processed.
• PCMark 8 Storage Benchmark 2.0
  • A test based on emulating real disk load, which is typical for various popular applications. On the tested drive, a single partition is created in the NTFS file system for the entire available volume, and the Secondary Storage 2.0 test is carried out in PCMark 8. As test results, both the final performance and the speed of execution of individual test traces generated by various applications are taken into account.
• Real file load tests
  • Measuring the speed of copying directories with files of different types. For copying, a standard Windows tool is used - the Robocopy utility, as a test set, a working directory is used, including office documents, photographs and illustrations, pdf-files and multimedia content with a total volume of 8 GB.
  • Measuring the speed of archiving files. The test is carried out with the same working directory as the copying, and the 7-zip archiver version 9.22 beta is chosen as a tool for compressing files. The Deflate method is used to reduce the impact of processor performance.
  • Research of archive unfolding speed. The test is carried out with an archive obtained by measuring the archiving speed.
  • Evaluation of the speed of launching a game application. Measures the performance of the disk subsystem when executing a script captured when launching Far Cry 4 and loading a custom save level into it. To minimize the impact of processor and memory performance, all delays that occur due to their fault were removed from the test scenario.
  • Evaluation of the startup speed of applications that form a typical working user environment. The performance of the disk subsystem is measured when executing a script captured when running an application package that consists of the Google Chrome browser, Microsoft Word text editor, Adobe Photoshop graphics editor, and Adobe Premiere Pro video editor with working files. To minimize the impact of processor and memory performance, all delays that occur due to their fault were removed from the test scenario.

Today is clearly the right time to get a new, capacious and fast solid state drive. After a long fall in prices, a solid-state terabyte can cost even less than 10 thousand rubles, and it’s a sin not to take advantage of this opportunity. At the same time, we again, with the numbers "on hand", urge you to focus primarily on drives with an NVMe interface. These are obviously more modern models that are based on high-quality flash memory and provide significantly higher performance compared to the outdated SATA SSDs.

Testing has shown that in everyday interaction with a PC, during normal file operations, or when downloading games and programs, NVMe drives can provide more than a twofold speed advantage over SATA counterparts, and to get it, it is absolutely not necessary to resort to buying expensive models. Even the most affordable NVMe SSDs, whether bufferless or based on QLC memory, can offer better responsiveness and better read and write speeds.

However, it must be remembered that the performance gap of various NVMe drives can be very noticeable. The PCI Express 3.0 x4 bus they use has a high bandwidth, which practically does not hinder the potential of current SSD platforms. As a result, the differences between strong and weak offerings in the NVMe world are much more serious than they were in the era of SATA dominance. And this means that the choice of NVMe SSD should be approached very carefully.

Above, we have already given a graph comparing the average performance of current terabyte NVMe SSDs, but the issue of performance was considered in isolation from the price factor. In order to move from general words to specific recommendations, we have compiled a traditional price-performance map, which combines the average speed of SSDs according to the results of testing and their average cost according to Yandex.Market (for Moscow as of 07/26/19 ).

The above illustration hardly needs any detailed comments. Therefore, we can only issue a list of recommended models for purchase.

Top performance

For those who want to get the most out of the disk subsystem, the recommendation is quite expected. Samsung's flagship solutions have the highest performance among consumer drives. First of all, of course, Samsung970 PRO- An uncompromising and unique NVMe SSD based on MLC 3D V-NAND. The use of two-bit memory allows you to get not only outstanding performance, provided without any tricks like SLC caching, but also an extremely high level of information storage reliability. The problem with such an SSD is only one - its high price. But for those who are not ready to overpay, in the assortment of the South Korean manufacturer there is an option almost no worse - Samsung970 EVOPlus. This drive is based on the advanced fifth generation TLC 3D V-NAND and is comparable in performance to the 970 PRO at a price of one and a half times lower. Frankly, we don't see any good reason to overpay for the 970 PRO at all: the more affordable 970 EVO Plus model, without a doubt, is capable of satisfying the needs of any demanding enthusiast.

Rational option

If you give up a little on the performance requirements of the drive, then among the models on the market you can find a lot of interesting options with an advantageous combination of price and performance. Leader among them ADATAXPGGammixS11Pro(or his alter ego without a pre-installed heatsink XPGSX8200Pro), but depending on the situation, any other drive with an SMI SM2262EN controller may be more attractive. For example, it would also be a good option to purchase KingstonKC2000 - A fresh NVMe drive that uses avant-garde BiCS4 memory in conjunction with the SM2262EN controller.

In addition, there will certainly be those who consider it rational to purchase a drive based on the Phison PS5012-E12 controller. SiliconpowerP34A80 . It loses in performance to alternatives on the SM2262EN controller, but its manufacturer readily compensates for this with a lower price. At the same time, you should not be afraid of a product from a third-tier company: everything in this drive, with the exception of the label, is made by Phison itself.

First level

A good option can be selected even when the budget allocated to the drive is extremely limited. Among those terabyte NVMe SSDs that can be purchased at the price of SATA models, we would first of all recommend paying attention to models built on QLC 3D NAND, in particular CrucialP1 or IntelSSD660p. Due to the use of flash memory with four-bit cells, these SSDs are amazingly cheap, but at the same time they are based on a fairly good SMI SM2263 controller and have a full-fledged DRAM buffer, due to which they do not lose much in performance to more expensive models. If QLC memory seems to you a dubious thing, even though it has been on the market for a long time and does not cause any complaints about reliability, pay attention to TranscendMTE110S. The more familiar TLC 3D NAND is used here, and the low price is ensured by the lack of a DRAM buffer, which is compensated with variable success by HMB technology.

The article is devoted to the analysis of the performance of solid state drives and hard drives. An article has already been presented on our website, which describes in detail the pros and cons of SSD. But this time I would like to focus on comparing the speed characteristics of these devices and tell in detail how great the advantage of solid state drives is.

Quite often we hear that the superiority of SSD in performance is not so significant - "only" 3-4 times. For example, the maximum speed of advanced hard drives is about 160-170 MB / s, while an SSD can show about 550 MB / s. A simple calculation gives a difference of almost 3.5 times. However, the processes that occur when reading information from the media are much more complicated, and it is incorrect to directly compare the maximum speeds.

Test results for SSD Vertex 3 and HDD Seagate 3 TB
(clickable)

Take a look at the test results for two devices using the popular CrystalDiskMark software. It will allow you to compare both types of drives in different operating modes. The first drive is an SSD manufactured by OCZ called Vertex 3, which has very high performance. The second is a modern 3TB Seagate hard drive with very high performance. We can say that some of the best representatives of each market segment are compared.

The top number on the left is the linear read speed when data is read sequentially. In this mode, almost all types of media show their maximum capabilities. The hard disk does not have to constantly move heads, and most of the time is spent reading and transferring data. The solid state drive, in turn, transmits data in large blocks, while using all channels. This behavior of devices is usually observed when copying huge files - movies, archives, DVD images. The speed difference between the two devices is 3.27 times.

The second row of numbers is reading in 512k blocks. The hard drive starts spending more time moving heads looking for each block, so the speed slows down. An SSD has to do more calculations to access different flash memory cells. Please note that SSD performance is 92% of the maximum, while a conventional hard drive is only 37%. This behavior corresponds to copying a set of small photos and illustrations or audio files.

The next row is reading in very small blocks of 4 KB. It is in this test that the speeds sag the most. A classic hard drive spends the lion's share of time moving heads in search of the right pieces of information, and a hard drive performs a huge amount of calculations to find the right cells. As a result of this, the speed of the hard drive dropped by 220 times, and that of the SSD - only 15 times. The speed difference between the two tested devices on 4K blocks is 52 times. This mode of operation corresponds to the process of loading the operating system, launching applications and copying text documents - that is, the most frequent operations on a PC.

Now it's time to talk about the parallel execution of operations. While working on a computer, many processes are running in the system - programs and applications, system utilities, services that can access the drive at any time. It turns out that at one point in time several requests for reading can come. The hard disk is forced to process them one at a time - the heads can only read one file at a time. But the SSD has several memory chips that store information. Therefore, you can process several requests at once, and all of them will be executed in parallel.

The last line just shows the speed of work on 4K blocks with a request queue of 32. That is, the situation is simulated when you need to read 32 files of this size at once. As you can see, the hard drive has almost no differences in parallelization, since it can only receive one file at a time, and the SSD reads data in several streams, which allows you to increase performance by 5.25 times. A small difference in speeds between a hard drive with and without a queue is due to the presence of NCQ technology, which somehow arranges this very queue so as not to “run back and forth 2 times”.

For the sake of objectivity, it should be noted that such a deep queue almost never occurs in real conditions. For example, when the operating system boots, the queue value is approximately four.

In other words, if in theory (according to the documentation) the devices differ by 3.5 times, then in real operations when the computer is running, the difference can reach much larger values.

The right column in the program window is the results of the recording, for which all of the above is true.

Comparison of speed distribution of SSD (bottom) and HDD (top)

But that's not all. Take a look at the other graphics made by HD Tune. They show the distribution of speeds over the storage space (blue line). The left part corresponds to the beginning of the disk, the right part corresponds to the end. If the SSD gives the same speed on almost the entire volume, then by the middle of the space, reading (and writing) seriously sags in the hard drive, and at the end it drops by more than 2 times. In practice, this means that if the operating system was installed on a full disk, or the last partition on the device, then the performance of the drive will be noticeably lower than declared. The same goes for the access time (yellow dots), which grows as you move towards the end of the disk space.

It turns out, the initial superiority of 3.5 times in practice can result in both 100 and 200 times. And this is compared with the best samples of hard drives. There is nothing to say about ordinary disks with average characteristics. So buy an SSD as soon as possible.

Until recently, when buying a new computer and choosing the drive to install, the user had the only choice - the HDD hard drive. And then we were only interested in two parameters: spindle speed (5400 or 7200 RPM), disk capacity and cache size.

Let's look at the pros and cons of both types of drives and make a visual comparison of HDD and SSD.

Principle of operation

A traditional drive, or as it is commonly called ROM (Read Only Memory), is necessary to store data even after a complete power outage. Unlike RAM (Random Access Memory) or RAM, data stored in memory is not erased when the computer is turned off.

A classic hard drive consists of several metal "pancakes" with a magnetic coating, and data is read and written using a special head that moves above the surface of the disk rotating at high speed.

Solid-state drives have a completely different principle of operation. An SSD has no moving parts at all, and its “innards” look like a set of flash memory chips placed on a single board.

Such chips can be installed both on the system motherboard (for especially compact models of laptops and ultrabooks), on a PCI Express card for desktop computers, or on a special laptop slot. The chips used in SSDs are different from what we see in a flash drive. They are much more reliable, faster and more durable.

Disk history

Hard magnetic disks have a very long (of course, by the standards of the development of computer technology) history. In 1956, IBM released a little-known computer IBM 350 RAMAC, which was equipped with a 3.75 MB storage device that was huge by those standards.

These cabinets could store as much as 7.5 MB of data

To build such a hard drive, 50 round metal plates had to be installed. The diameter of each was 61 centimeters. And all this gigantic construction could store… just one MP3-composition with a low bitrate of 128 Kb/s.

Up until 1969, this computer was used by the government and research institutes. Some 50 years ago, a hard drive of this size was quite suitable for mankind. But the standards changed dramatically in the early 80s.

5.25-inch (13.3 cm) floppy disks appeared on the market, and a little later, 3.5- and 2.5-inch (notebook) versions. Such floppy disks could store up to 1.44 MB of data, and a number of computers of that time were supplied without a built-in hard drive. Those. to start the operating system or program shell, you had to insert a floppy disk, then enter a few commands, and only then get to work.

In the entire history of the development of hard drives, several protocols have been changed: IDE (ATA, PATA), SCSI, which later transformed into the now well-known SATA, but they all performed the only function of a “connecting bridge” between the motherboard and the hard drive.

From 2.5 and 3.5-inch floppy disks with a capacity of one and a half thousand kilobytes, the computer industry has moved to hard disks of the same size, but with a thousand times more memory. Today, top 3.5-inch HDDs are up to 10 TB (10,240 GB); 2.5-inch - up to 4 TB.

The history of SSDs is much shorter. About the release of a device for storing memory, which would be devoid of moving parts, engineers thought back in the early 80s. The appearance in this era of the so-called bubble memory was met with very hostility and the idea proposed by the French physicist Pierre Weiss back in 1907 did not take root in the computer industry.

The essence of bubble memory was to divide the magnetized permalloy into macroscopic regions that would have spontaneous magnetization. The unit of measure for such an accumulator was bubbles. But the most important thing is that there were no hardware moving elements in such a drive.

Bubble memory was forgotten very quickly, and was remembered only during the development of a new class of drives - SSD.

SSDs only appeared in laptops in the late 2000s. In 2007, the budget laptop OLPC XO-1 entered the market, equipped with 256 MB of RAM, an AMD Geode LX-700 processor with a frequency of 433 MHz and the main highlight - 1 GB NAND flash memory.

The OLPC XO-1 was the first laptop to use a solid state drive. And soon the legendary line of netbooks from Asus EEE PC with the 700 model joined it, where the manufacturer installed a 2-gigabyte SSD drive.

In both laptops, the memory was installed directly on the motherboard. But soon, manufacturers revised the principle of organizing drives and approved a 2.5-inch format connected via the SATA protocol.

The capacity of modern SSD drives can reach 16 TB. Most recently, Samsung introduced just such an SSD, however, in a server version and with a space price for the average layman.

Pros and cons of SSD and HDD

The tasks of drives of each class come down to one thing: to provide the user with a working operating system and allow him to store personal data. But both SSD and HDD have their own characteristics.

Price

SSDs are much more expensive than traditional HDDs. To determine the difference, a simple formula is used: the price of the drive is divided by its capacity. As a result, the cost of 1 GB of capacity in currency is obtained.

So, a standard 1 TB HDD costs an average of $50 (3300 rubles). The cost of one gigabyte is $50 / 1024 GB = $0.05, i.e. 5 cents (3.2 rubles). In the SSD world, everything is much more expensive. An SSD with a capacity of 1 TB will cost an average of $ 220, and the price for 1 GB according to our simple formula will be 22 cents (14.5 rubles), which is 4.4 times more expensive than an HDD.

The good news is that the cost of SSDs is rapidly declining: manufacturers are finding cheaper solutions for the production of drives and the price gap between HDDs and SSDs is narrowing.

Average and maximum capacity of SSD and HDD

Just a few years ago, between the maximum capacity of HDD and SSD, there was not only a numerical, but also a technological gap. It was impossible to find an SSD that could compete with HDD in terms of the amount of stored information, but today the market is ready to provide the user with such a solution. True, for impressive money.

The maximum capacity of SSDs offered for the consumer market is 4TB. Similar option at the beginning of July 2016. And for 4 TB of space you will have to pay $1499.

The base HDD capacity for laptops and computers released in the second half of 2016 ranges from 500 GB to 1 TB. Models similar in power and characteristics, but with an installed SSD drive, are content with only 128 GB.

SSD and HDD speed

Yes, it is for this indicator that the user overpays when he prefers SSD storage. Its speed is many times higher than that of HDD. The system is able to boot in just a few seconds, it takes much less time to launch heavy applications and games, and copying large amounts of data from a multi-hour process turns into a 5-10 minute process.

The only “but” is that data from an SSD drive is deleted as quickly as it is copied. Therefore, when working with an SSD, you may simply not have time to press the cancel button if one day you suddenly delete important files.

Fragmentation

The favorite "delicacy" of any HDD hard drive is large files: MKV movies, large archives and BlueRay disk images. But as soon as you load the hard drive with a hundred or two small files, photos or MP3 compositions, the read head and metal pancakes become confused, as a result of which the recording speed drops significantly.

After filling up the HDD, repeatedly deleting/copying files, the hard disk starts to work more slowly. This is due to the fact that parts of the file are scattered over the entire surface of the magnetic disk, and when you double-click on a file, the reading head is forced to look for these fragments from different sectors. This is how time is wasted. This phenomenon is called fragmentation, and as a preventive measure to speed up the HDD, a software and hardware process is provided defragmentation or ordering such blocks/parts of files into a single chain.

The principle of operation of the SSD is fundamentally different from the HDD, and any data can be written to any sector of memory with further instant reading. That is why defragmentation is not needed for SSD drives.

Reliability and service life

Remember the main advantage of SSD drives? That's right, no moving parts. That is why you can use a laptop with an SSD in transport, off-road or in conditions inevitably associated with external vibrations. This will not affect the stability of the system and the drive itself. The data stored on the SSD will not be affected even if the laptop falls.

HDDs are exactly the opposite. The read head is located only a few micrometers from the magnetized discs, and therefore any vibration can lead to the appearance of "bad sectors" - areas that become unusable. Regular pushes and careless handling of a computer that runs on an HDD will lead to the fact that sooner or later such a hard drive will simply, in computer jargon, “crumble” or stop working.

Despite all the advantages of SSDs, they also have a very significant drawback - a limited use cycle. It directly depends on the number of memory blocks rewriting cycles. In other words, if you copy/delete/recopy gigabytes of information every day, you will very soon cause the clinical death of your SSD.

Modern SSD drives are equipped with a special controller that takes care of evenly distributing data across all SSD blocks. So it was possible to significantly increase the maximum operating time up to 3000 - 5000 cycles.

How durable is an SSD? Just take a look at this picture:

And then compare with the warranty period of operation, which is promised by the manufacturer of your particular SSD. 8 - 13 years for storage, believe me, not so bad. And do not forget about the progress that leads to a constant increase in the capacity of SSDs at an ever-decreasing cost. I think in a few years your 128 GB SSD will be a museum piece.

Form factor

The battle of drive sizes has always been caused by the type of devices in which they are installed. So, for a desktop computer, the installation of both a 3.5-inch and a 2.5-inch drive is absolutely uncritical, but for portable devices, such as laptops, players and tablets, a more compact version is needed.

The 1.8-inch format was considered the smallest serial version of the HDD. This is the disc used in the discontinued iPod Classic.

And no matter how hard the engineers tried, they failed to build a miniature HDD-hard drive with a capacity of more than 320 GB. It is impossible to break the laws of physics.

In the world of SSD, everything is much more promising. The generally accepted 2.5-inch format has become such not because of any physical limitations that technologies face, but only because of compatibility. In the new generation of ultrabooks, the 2.5 '' format is gradually being abandoned, making the drives more and more compact, and the cases of the devices themselves thinner.

Noise

The rotation of disks even in the most advanced HDD hard drive is inseparably linked with the occurrence of noise. Reading and writing data sets the disk head in motion, which rushes around the entire surface of the device at insane speed, which also causes a characteristic crackle.

SSD drives are absolutely silent, and all processes occurring inside the chips take place without any accompanying sound.

Outcome

Summing up the comparison of HDD and SSD, I want to clearly define the main advantages of each type of drive.

Advantages of HDD: capacious, inexpensive, accessible.

HDD Disadvantages: slow, afraid of mechanical influences, noisy.

Advantages of SSD: absolutely silent, wear-resistant, very fast, have no fragmentation.

Disadvantages of SSD: expensive, theoretically have a limited service life.

Without exaggeration, we can say that one of the most effective methods for upgrading an old laptop or computer is installing an SSD drive instead of an HDD. Even with the latest version of SATA, you can achieve a threefold increase in performance.

Answering the question of who needs this or that drive, I will give several arguments in favor of each type.

Of course, this is the main difference between them, but not the only one.

Types of computer memory

Memory in a computer is the place where data is stored. Memory is divided into ephemeral(such as RAM or RAM) that retains data only as long as the computer is running, and permanent(non-volatile) that retains data even after power is turned off.

It can also be divided by device, or rather, by type. Can be distinguished magnetic media(e.g. hard drives HDD, SSHD), optical, semiconductor and flash memory.

Differences between HDDs and SSDs

Carrier design

The main difference that first comes to mind is the internal structure.

Hard drives HDD are magnetic storage media. To read them, a special, movable head is used, which moves along the round magnetic plates used to store data, and thus searches for files.

SSD media is classified as flash memory built only from NAND Flash cells. This allows you to read and write files on the SSD much faster - all due to the fact that reading occurs without the participation of moving elements. Moving parts must arrive at a file location and cannot be present in multiple locations at the same time (which makes reading or writing multiple files even slower).

Loudness during operation and resistance to damage

Movable elements are also responsible for the appearance of noise during the operation of the disk. Without these moving parts, SSDs are silent. In addition, they are also more resistant to damage (again, this is due to the absence of mechanical parts that can move, for example, in the event of a fall).

The AHCI protocol was created for HDD hard drives, at a time when no one was expecting faster media to appear. Later SSDs had a huge potential in terms of data flow, however, it was severely limited by an outdated protocol.

For new fast hard drives, a new NVMe protocol was created. Its capabilities are shown in the table below:

HDD Seagate 1 TB
Read speed: 169 Mb/s Write speed: 186 Mb/s
Uninterrupted and high performance 7200 RPM HDD. Thanks to this, the launch and loading of programs is much faster. The drive is also equipped with MTC (Multi-Tier Caching) technology, which optimizes data flow and speeds up writing and reading.
ADATA SSD 128 GB
AHCI protocol Read speed: 560 Mb/s Write speed: 300 Mb/s
128 GB hard drive. Equipped with NAND Flash cells and SMI controller. The DRAM cache and SLC intelligent caching system further enhance its performance.
Solid state drive GOODRAM 240 GB
Reading speed: 550 Mb/s Write speed: 320 Mb/s
One of the most durable and reliable solid state drives. Equipped with features such as SmartRefresh, SmartFlush and GuaranteedFlash that protect data in case of power surges.
Samsung 250 GB 960 EVO Solid State Drive
NVMe protocol Read speed: 3200MB/s Write speed: 1500MB/s
The NVMe interface provides superior read and write speeds. Reading speed is even faster thanks to Turbo Write technology. Dynamic thermal protection prevents overheating.

When a PC gamer wonders what are the most important tuning options, in addition to the mandatory purchase of a powerful graphics card and processor, we give him the following advice: replace your classic hard drive with an SSD drive. Just buy not a SATA-SSD, but a flash drive that transfers data via PCI-Express and uses the NVMe protocol for this.

Such models achieve five times higher data transfer rates, and this technology practically does not know the upper limit. Currently, the market is more and more filled with such turbo drives (albeit still quite expensive), so the gamer is faced with the question of whether he is ready to invest a little more money in a significant increase in speed or give preference to the classic, relatively slow SSD.

A New Era of Turbo SSDs

To replace the HDD, you could not think about anything special - just buy a drive of the volume you need. Over time, things got a little more complicated, since the SATA interface was originally designed to work with the AHCI (Advanced Host Controller Protocol) protocol and the corresponding driver for slow classic spinning disk drives.
An unfortunate side effect: the SATA-600 interface allows a maximum data transfer rate of 600 MB/s.

If you look at ours, you can see that many models reach an average data transfer rate (when reading) already above 550 MB / s, and when writing on their "speedometer" you can often see 540 MB / s. Thus, it becomes obvious that this technology no longer has the potential for growth in indicators.

In other words, the SATA interface can become the so-called "bottleneck" for flash drives, which are getting faster and faster. It's good that new SSDs bypass this speed limit if they use PCIe connectors instead of red SATA cables - that is, use the type of connection that was traditionally used for graphics cards. A single PCIe 3.0 lane can theoretically transfer up to 1 GB/s.

Tiny NVMe-SSDs like the new Samsung PM971 are also suitable for ultrabooks or tablets - they are only two centimeters

In this test, four such lines were used to connect SSD drives. Thus, this gives a maximum of 4 GB / s - at least in theory. In practice, this indicator is not achieved: the latest Samsung 960 Pro demonstrated the highest data transfer rate to date with a result of 2702 MB / s when reading.

This is significantly faster than any of the SATA-SSDs, and the interface is not yet at its full potential: data transfer speeds are currently limited by the type of flash memory used and by storage media controllers.

It might be interesting:

Two different types of connectors

Unlike SATA drives, when buying a turbo SSD, you should pay attention to the correct choice of its form factor. Fast data storage can be produced both in the form of expansion cards inserted into the PCIe slot, and in the form of memory strips that are installed in the so-called M.2 slots.

Thus, before purchasing the model you like, we recommend that you take a look at the motherboard and check if the interface of the appropriate type is presented there.

Many SSD manufacturers develop software that analyzes the health of NVMe-SSDs. Intel calls it Solid-State Drive Toolbox

This tip is especially true for older motherboards, since their M.2 slot can only output the SATA bus for data transfer. Those who assemble a new computer for themselves may not bother with this issue: motherboards for new processors have M.2 connectors with a PCIe connection and support the new Non-Volatile Memory Express (NVMe) data exchange protocol - this provokes a second turbo- leap.

Unlike models for M.2, SSDs in the form of a PCIe card can also be interesting for upgrading older systems. However, you should definitely make sure that there is one more free PCIe slot on the motherboard in addition to the one occupied by the graphics card.

And one more small detail can be very important: of the six SSDs taken for this test, four have an expansion card form factor, but only three of them support the PCIe 3.0 standard. Kingston HyperX Predator is limited to only PCIe 2.0, which is only capable of passing 500 MB / s through the line.

While your read and write speeds of 1400MB/s and 1010MB/s respectively will be significantly better than SATA competitors here, they can't match the performance of the fastest SSDs. At the same time, media that supports PCIe 3.0 will work in a PCIe 2.0 slot, but their speed will be significantly reduced.

Overheated SSD drives become slower

Angelbird Wings PX1 PCIe card adapter with its own heatsink prevents Samsung 950 Pro from overheating

Currently, we can expect data transfer rates in excess of 2.5 GB/s from PCIe SSDs. OCZ's M.2 SSDs come standard with a PCIe adapter. According to the results of our measurement results, we see it as more than rational to leave the device in it. We measured the performance of these devices for M.2 and without an adapter, registering slightly worse values: for example, when reading, a speed of only 2382 MB / s was achieved, which is about 130 MB / s less than with the adapter.

Very short reaction time

High data transfer speeds are good for speeding up downloads, but the reason that Windows and games with an SSD drive in a computer run noticeably faster in a computer is hidden primarily in the low latency. During testing, we study it during I / O measurements (Input / Output), that is, counting the number of read or write operations performed per second when processing sequentially located memory blocks. This parameter, the so-called IOPS (Input/Output Operations Per Second), is the missing "ingredient" for a fast PC, which is often heavily loaded.

In this scoring discipline, the OCZ RD400 drive has the advantage with 43,974 IOPS when writing. In reading, on the contrary, the result of 18,428 IOPS is not even half of the previous one. Here, our leader of the rating, Samsung 960, can observe the same heterogeneity of characteristics: when writing, it reaches 42,175 IOPS, and when reading - only 29,233.

An enviable similarity of results is demonstrated by Zotac with its approximately 35,000 IOPS (both reading and writing). However, when comparing products, this parameter often has to be combined with others. At the same time, turbo SSDs should soon “break through” the psychologically important mark of 100,000 IOPS.

The Kingston HyperX Predator performed the worst, with around 23,000 read IOPS and 17,800 write IOPS in last place, by a wide margin. The main reason for this is outdated technology, since this SSD drive still transfers data using the AHCI protocol. The new NVMe access protocol, on the other hand, is optimized to work with SSDs.

The advantages of NVMe manifest themselves primarily in the parallelization of processes: the data transfer protocol allows you to work with queues of input / output requests (I / O queues) up to 65,536 commands in size. The AHCI protocol is limited to only one queue of 32 commands, which can cause data clutter under heavy load.

Top 10 NVMe SSDs Value for Money

Even the new ultra-fast drives are slowly dropping in prices, and the cheapest NVMe-enabled SSD can already be found at the price of SATA drives, And this is good news. We have selected for you the 10 best NVMe-enabled SSD flash drives in terms of price / quality ratio.