Review of Samsung's stylish Galaxy Alpha (SM-G850F). Samsung Galaxy Alpha (SM-G850F) Review

The Samsung SSD 840 PRO family has been on the market for two years now, and our tests have consistently ranked the top drives - although quite a few other high-end SSDs have appeared during that period. Even today, the 840 PRO is able to compete for the leading position, but Samsung has prepared a new leader - the SSD 850 PRO. But in this case, the development is not only evolutionary, as Samsung first used 3D V-NAND memory in a consumer-grade SSD. Unlike MLC NAND memory, the new type of memory promises to be more reliable and faster, and also provides a higher level of storage density.

Samsung's biggest innovation is in the flash memory it uses. More recently, we highlighted the technology leadership of Crucial, which uses 16nm MLC NAND at 256Gbps per die, but Samsung has gotten more radical changes. Last year, the first family (3 bits per cell) appeared to receive our award. The new Samsung SSD 850 PRO range has undergone a fundamental change in flash memory technology.

All types of SLC, MLC or TLC flash memory have one thing in common: the cells are two-dimensional, that is, they are located on the plane of the crystal. And to increase the memory capacity, it is necessary to increase the die area. Of course, today manufacturers install "sandwiches" of several memory crystals, which allows chips to be increased in height, and not just in area. But here, too, not everything is going smoothly, since the quality of the signals for crystals in such a stack decreases. In Samsung's case, 3D V-NAND memory cells are already three-dimensional, they are concentric cylinders and can be stacked much easier.

The technical specifications are shown in the following table:

Manufacturer and model	Samsung SSD 850 PRO
Retail price	1 TB: € 729 512 GB: 469 € 256 GB: 239 € 128 GB: 140 euros
Products webpage	www.samsung.com
Technical specifications
Form factor	2,5"
Capacity (manufacturer information)	128, 256, 512 GB, 1 TB
Capacity (after formatting)	119, 238, 477, 954 GiB
Other capacity options	128, 256, 512 GB, 1 TB
Cache memory	128GB: 256MB (LPDDR2) 256-512 GB: 512MB (LPDDR2) 1TB: 1GB (LPDDR2)
Controller	Samsung MEX
Memory chips	3D V-NAND
Reading speed (manufacturer information)	550 MB / s
Write speed (manufacturer information)	520 MB / s (128 GB: 470 MB / s)
Manufacturer's warranty	Ten years
Contents of delivery	-

We'll first look at the technology of the new 3D V-NAND flash memory, and then move on to benchmarking Samsung's new 850 Pro family.

If you want an SSD with incredible speed and endurance, the Samsung SSD 850 PRO gives you both and more. Powered by Samsung V-NAND, it's designed to handle heavy workloads on workstations and high-end computers with IT heavy users in mind. Plus, it boasts an industry leading 10-year limited warranty for client PCs.

It all adds up to performance

The 850 PRO delivers a new level of performance beyond your expectations for sequential reads of up to 550 MB / s and random reads up to 100,000 IOPS. Plus, achieve over 2x * faster performance with RAPID mode enabled by Magician software to processes data on a system level using DRAM as cache. * These results were determined by PCMARK ® 7 testing with scores of 7,864 and 20,172 with RAPID mode off and on using a 4TB drive.

Elevate the endurance level

With heavy workloads, endurance is everything. The 850 PRO is a game changer, with standing up to 600 terabytes written (TBW) and backed by a 10-year limited warranty. * Dynamic Thermal Guard protects it from overheating while an AES 256-bit hardware-based encryption engine secures your data and is compliant with TCG ™ Opal standards and IEEE® 1667 protocol. * 10-year warranty or TBW (256 GB: 150 TBW, 512 GB / 1 TB: 300 TBW, 2 TB: 450 TBW, 4 TB: 600 TBW), whichever comes first.

Seamless, synergistic integration

Leverage our world-class integration expertise. Samsung designs every component of the SSD in house, including the V-NAND flash memory, controller, DRAM and firmware - all fine-tuned to work in perfect synergy.

Currently, there is a huge selection of good, or at least not bad solid state drives, in different containers. They differ in controllers, memory type, and sometimes interface. In this environment, it is not easy to make a decision in favor of one or the other drive, so in this article I want to consider two similarly positioned Samsung 850 and Kingston A400 models.

Theory and positioning

Both models belong to the budget sector and cannot show off super-performance, on the other hand, they also have to cope with the main tasks - to accelerate the work and game applications of users, the operation of the operating system and files relative to hard drives. Here I have no doubt that they will cope with the task. And yet, let's compare the characteristics:

In terms of its characteristics, the Samsung drive outperforms the Kingston drive a little, however, it is also a little more expensive in price, but we must remember that these are just numbers on paper. All the numbers not confirmed by tests have already turned out to be both more and less (depending on the case), so we will not run far ahead.

It is important to note that 120GB is still one of the most popular storage capacities among users. An inexpensive disc purchase can guarantee all the benefits that have already been mentioned above. For most users, a 120GB SSD can be a conduit into the world of solid state drives and dramatically improve the performance of their computer. For example, any OS with all updates, an office package and a number of “usual” home applications can be installed on a 120 GB disk without any problems. The only thing that can cause caution in choosing such a volume (apart from speeds) is a large number of games that would also be nice to be placed on an SSD. However, even 120GB drives can accommodate at least multiple AAA titles, unless you are trying to install multiple 60GB titles at once.

I ordered both CDs from a store and at that time they were selling at a very good price. Looking ahead, you can periodically check the SSD product page for the best discounts. Thus, you can get prices cheaper than in our stores, although, of course, you will have to wait for a while.

Delivery to Moscow took 15 days, I don't think it's long for international delivery (by the way, there are a lot of free shipping options). The parcel arrived in in the best possible way, I barely opened the package, because it was very dense, and was additionally secured with tape and films. Inside, both boxes were in perfect condition, wrapped in a shock-absorbing soft film with pimples. Let's start examining the contents of the package.

Appearance and features of Samsung 850 and Kingston A400

The devices are supplied in different packages. The Samsung drive is in a regular cardboard box, while the Kingston device is sealed in a hard plastic wrap. Both fulfill their role as protection against minor damage and provide information about the devices in them.

The disks are of a budget class, therefore, as such, the bundle is not provided, except that the user's manual is in the Samsung box. This is not a disadvantage for inexpensive discs, because this approach saves the user money.

Both drives are built on the basis of 2.5 ”cases of a thin 7 mm format, which allows them to be installed not only in the case of system units, but also in a wide range of monoblocks, mini-PCs and laptops.

The devices are assembled in rough, pleasant-to-the-touch cases. Interestingly, Samsung did not immediately select the 850 series. Initially, there were 850 EVO, then, for some reason, the younger representatives of the 120 GB model were removed from it and simply "850" was allocated in a separate series.

Also, both discs on top contain only stylistic elements and logos, and on the back they have labels with additional, mainly technical information. In this case, both SSDs get 120GB of storage.

Also, the drives are equal in terms of using the SATA 6 Gb / s interface, in a word, they have a lot in common, but what they have inside.

The stuffing of Samsung disks is understandably 3D TLC memory made by Samsung itself, which works in conjunction with the MGX controller, also produced by this manufacturer. With the Kingston disc, everything is not so simple, as we will see right now. So we run special utility for memory recognition (the controller is installed in the device Phison S11). And we see that:

Installed Micron memory with MLC class of cells, and not TLC, as indicated by the manufacturer. I have nothing to worry about, because it's even good. In fact, I just got better stuffing than stated, which should especially affect write speeds. It remains to compare the disks with each other, will this fight be equal, knowing that the A400 is "in a different weight" with the memory of a higher class? Personally, I think yes. Let not everyone be as lucky as I am, but someone is quite lucky, which means that the buyer can count on a certain amount of luck. Moreover, this does not affect the price in stores.

Samsung 850 and Kingston A400 benchmarks and performance

SSD-Z recognizes little information about both drives, probably Phison and Samsung controllers seem closer to it than some others.

In CrystalDiskMark we see the first significant differences between the two drives, which are worth taking a closer look at. So, the Samsung 850 gets a noticeably higher result in the heaviest 4K mode - 36 MB / s versus 30 MB / s, as well as 110 MB / s versus 82 MB / s in writing with this setting profile. However, the Kingston A400 wins noticeably at 559 MB / s sequential read speeds. Samsung is again slightly ahead in write performance: 522 MB / s versus 506 MB /. However, in the mode of one stream with a queue depth of 32 (Q32T1), the Kingston disk wins 259 MB / s against 241 MB / s. An interesting difference between devices. You can study the results for a rather long time, it is clear that they differ, depending on the specific scenario, then one disk turns out to be faster, then the other.

The write speed stability test also shows interesting results. Kingston A400 wrote the file faster. More precisely, 1/3 of the distance traveled was written at a speed of ~ 400 MB / s, then there was a drop to 200 MB / s, and the final section of the "path" was covered by the disk at a speed of 227 MB / s. As for Samsung, it went through almost half at 320MB / s, then dropped to 155MB / s (hello TLC memory!). As a result, Kingston is ahead of the linear recording of files, and the larger the file (s), the greater the advantage of the Kingston drive. However, here our model "cheats" by using MLC memory, which is more stable in dealing with write operations.

Now let's move on to the IOPS results and the situation is reversed again. The Kingston A400 scores up to 48,000 read IOPS, and the Samsung 850 scores 69,000 IOPS. A similar picture is observed in the write speed. The A400 has a write speed of 79,000 IOPS and the 850 has 86,000 IOPS.

Read IOPS

Thus, in contrast to the established write speed and sequential operations, Samsung's IOPS is noticeably higher and this round remains behind it.

Read IOPS

The latest PC Mark 8 benchmark focused on bandwidth. In this test, the Kingston A400 drive is average, while the Samsung 850 is the best, by a wide margin.

It is worth noting that the 850 Pro 256 GB also showed the best result in this test, but already among the 250 GB SSD class. Thus, this is a certain feature of the platform.

conclusions

I tested two interesting and inexpensive solid state drives. Taking into account the discounts, the offer turned out to be quite profitable for the order. The results of both discs are extremely interesting. Overall, both SSDs look good and can significantly improve the comfort of using a computer or laptop, but they seem to be better suited for different tasks.

The Kingston A400 performs well at sequential read and write speeds. If you need to overwrite large files, it has a significant advantage. True, if you come across, like me, a model with MLC memory. But it's also a slightly cheaper SSD.

The Samsung 850 will benefit from faster I / O and small-block workloads to launch applications faster and perform complex read / write operations.

Since the result is quite balanced, which is rare when comparing different devices, I give both drives the Cost Effective award. And you can choose the SSD to your liking: the best work with files, or applications.

Over the past years, Samsung has been able to become one of the key players in the solid state drive market. The company's strategy lies in the complete vertical integration of production from start to finish, which allows it to keep the lead in the implementation of new promising technologies. By simultaneously developing and releasing both controllers and flash memory, the company gains a huge engineering advantage since commissioning and debugging new designs does not require any outside involvement. And we have already seen examples of the implementation of this advantage: here it is appropriate to recall the SSD of the 840 series, which became the first mass products based on three-bit TLC NAND. It was thanks to this technology that Samsung was able to conquer the mass flash drive market. Using inexpensive Samsung-made TLC memory, the 840 series, and later the 840 EVO, offered an excellent combination of performance and price, which ultimately made them one of the most popular solutions.

Now, two years after the introduction of TLC NAND, Samsung is once again making a major breakthrough in technology with the groundbreaking 850 Pro Series, the first consumer SSDs to use the all-new 3D MLC NAND. Despite the fact that the Samsung 850 Pro is officially on Russian market is not yet shipped, our laboratory was able to obtain and test a copy of the promising solid state drive... Whether this SSD will become a worthy successor to the traditions of the 840 Pro model and whether it will take the place of the best flash drive for personal computers, we will find out in this material.

⇡ Samsung V-NAND: the new flash paradigm in action

NAND memory has changed the entire storage market. Drives based not on traditional hard disk drives but on flash memory have been able to establish fundamentally higher levels of performance, and this has made them one of the most interesting computer technologies of the last decade. At the same time, NAND memory is far from a new invention. In fact, it appeared back in the 70s of the last century, but for a long time it simply could not penetrate consumer devices due to its high cost. However, technological progress in the end was able to make such memory affordable, and now it has become simply impossible to imagine a modern productive computer without an SSD stuffed with MLC or TLC NAND.

Improvements in semiconductor manufacturing processes used to make NAND crystals have played a major role in reducing the cost of flash memory. Reducing production rates reduces the area of ​​the resulting crystals, increasing the storage density in them of information, which ultimately leads to a decrease in the cost of solid-state drives. For example, the massive penetration of SSDs into the consumer market began with the transfer of flash memory crystal production from 50nm to 30nm processes. Nowadays, technical processes with rates less than 20 nm are in use, and the cost of flash drives quite naturally continues to fall.

However, it should be borne in mind that the improvement of technical processes to infinity is impossible. Moreover, manufacturers of flash memory are already feeling the imminent and imminent approach of technological limits. The fact is that with the thinning of production standards and a decrease in the geometric dimensions of transistors, the reliability characteristics of flash memory decrease. For example, memory produced using 50nm technology was able to withstand up to 10 thousand rewriting cycles, while today's 20nm NAND is designed at best for 3 thousand programming-erase cycles. In other words, there are serious obstacles to further scalability of traditional NAND memory, which, like other semiconductor devices, is still subject to Moore's Law.

Fortunately, all of this does not mean that progress will slow down. Fundamentally new ideas come to the rescue, making changes in the design principles of flash memory and allowing to increase the density of information storage without reducing the size of the cells.

The first such idea was an attempt to increase the capacity of cells when moving from SLC NAND to MLC and TLC memory, where each cell stores not one, but two or three bits of information. This is achieved by introducing a larger number of signal voltages. While SLC cells use only two voltage levels, corresponding to logic states 0 and 1, the MLC already uses four voltages, and the TLC uses eight. However, in reality, this path is a dead end. If the transition to MLC can be considered already a success, then there are very serious problems with TLC NAND, which, as practice shows, inhibits its spread. The point is that the use of a large number of voltages in the floating gate of the cell is possible only if this gate is massive enough to hold a significant number of electrons. But the introduction of technical processes with fine norms, on the contrary, reduces the size of the cells, so the release of TLC-memory using technologies of the 10-nm class becomes economically unprofitable. Not only the yield of suitable crystals decreases, but also the reliability of signal recognition, which requires the introduction of more complex schemes analog-to-digital conversion and data integrity control. Plus, another serious problem arises sharply - the mutual influence of cells, the electric field of which generates interference processes.

Obviously, some other approach is required. And an approach that should be a catalyst further development flash memory market over the next few years, is three-dimensional (3D) NAND. Its essence lies in the fact that instead of increasing the data storage density on the two-dimensional plane of a semiconductor crystal, it is proposed to switch to the use of vertical measurement and arrange cells not only planar, but also in layers.

The first to mass production of such a memory was able to enter Samsung, in whose performance this memory is called V-NAND (from the word Vertical), while other manufacturers such as Micron, Toshiba, SanDisk and SK Hynix are going to join promising technology during 2015.

The most interesting thing is that 3D NAND makes the race of nanometers completely unnecessary. For example, the same Samsung company, after introducing 19-nm technology for the manufacture of its planar memory, did not take the next step, but, on the contrary, with the transition to the release of V-NAND, rolled back to the 40-nm technical process. The high density of information storage, which is not inferior to the density of conventional NAND, which is produced by other manufacturers using 16-nm and 19-nm technical processes, was provided by a multilayer layout. But the main gain was found on the other hand: mature technologies and fairly large semiconductor elements significantly increased the memory resource and made it possible to avoid problems with a low yield of suitable crystals.

Samsung was able to introduce trial first-generation V-NAND SSDs last year. These pioneering, server-oriented SSDs have proven their worth. The memory used in them, which combines 24 vertical levels with cells, provided a 20 percent increase in performance, approximately doubled the reliability and significantly improved the economy of flash drives. This gave Samsung every reason to continue developing in the same direction. And now the company is ready to introduce the new technology to the mass market: the second generation V-NAND with 32 vertical levels and a new consumer storage based on it - the SSD 850 Pro, have appeared in Samsung's arsenal.

It should be noted that V-NAND not only assumes the arrangement of cells in layers, but also introduces some changes to the basic structure of flash memory cells. Along with the structural transformation, Samsung has taken advantage of the Charge Trap Flash (CTF) technology, a "charge trap flash" developed by the company's engineers back in 2006. The idea is that the charge is not stored in a doped polysilicon floating gate, but in a thin non-conductive silicon nitride layer. This technology is easily adaptable for three-dimensional design: the dielectric is placed between the control gate and the semiconductor channel in concentric cylinders, which ultimately increases the reliability of the entire circuit and reduces the likelihood of structural defects in multilayer production. In addition, CTF technology can reduce the voltage level required to program cells. And this, naturally, has a positive effect on their lifetime.

As a result, the Samsung V-NAND resource has grown significantly: the same 32-level flash memory crystals found in the Samsung 850 Pro can withstand up to 35,000 programming-erase cycles. That is, they are orders of magnitude more robust than modern flat MLC NAND, which is usually used in consumer SSDs. In addition, lowering the programming voltages has a positive effect on both power consumption and write performance.

Another important advantage of V-NAND is its compactness. The second-generation V-NAND semiconductor crystals used in the Samsung 850 Pro, produced using 40nm technology, have a capacity of 86 Gbps, while their area is about 95 mm 2. Thus, the storage density in V-NAND exceeds the storage density in 16nm planar flash memory chips manufactured by Micron by about 20 percent. In addition, Samsung, carrying out a full production cycle from start to finish, has the ability to pack up to 16 V-NAND cores in a single chip. And this means that the maximum volume of one three-dimensional flash memory chip can reach 172 GB.

Of course, many of the advantages of V-NAND technology will only appear later. For example, the SATA 6 Gb / s interface used today, coupled with the AHCI protocol, does not allow the full speed of the new memory to be revealed, and in future SSD models with the interface PCI Express she will be able to sparkle with new colors. Most importantly, 3D memory technology is highly scalable. The capacity of simple flat NAND chips is unlikely to exceed 128 Gbps, and V-NAND allows you to seamlessly add new layers and thus increase capacity. So, Samsung plans to release terabit crystals in 2017, and there is no reason why this milestone may not be taken. Along the way, V-NAND, produced according to fairly mature technical processes, can easily be transferred to a TLC design, and this will not lead to a catastrophic decrease in reliability. However on this moment such possibilities are not even considered, and in the coming years the emphasis will be on scaling memory in the vertical dimension.

In the near future, we can expect the widespread adoption of V-NAND in many Samsung products. For that memory, the company has launched a special plant in Xi'an, China, which is expected to reach full capacity by the end of this year. It is curious that the 40-nm process technology used at this plant made it possible to get by with fairly cheap production equipment, and the addition of new layers to three-dimensional NAND practically does not require any additional investment. For example, 32-layer memory is manufactured on the same production lines that previously produced 24-layer memory. And this means that another plus new technology there is the possibility of saving on technical re-equipment of production while increasing the density of data storage.

It turns out that V-NAND can boast all possible advantages, and at once. It has lower latencies, is very reliable, offers high storage density, is energy efficient, and its production cost is relatively low. And if such memory is placed in a drive with a modern controller, then it seems that an amazing model should turn out that will surpass everything that has been released so far. Has Samsung released such a model? Let's take a closer look at the 850 Pro.

⇡ Samsung 850 Pro Specifications

The new flagship Samsung 850 Pro drive is a logical continuation of the company's line of consumer SSDs. In doing so, Samsung is innovating strictly consistently, and V-NAND is the 850 Pro's only fundamental advantage over its predecessors. This drive continues to use the familiar SATA 6Gb / s interface and builds on the familiar eight-channel MEX controller found in the 840 EVO series for a long time. Moreover, the MEX controller, which is based on three cores with ARM architecture, in the new model even retained its operating frequency of 400 MHz. However, for the sake of fairness, we note that in the past flagship Samsung flash drive, the 840 Pro, the MDX controller similar in architecture worked at 300 MHz.

At the same time, the firmware of the Samsung 850 Pro has been almost completely rewritten. Support for V-NAND is implemented precisely through it, and the lower latencies for writing and erasing information offered by this memory, a higher resource of cells and all other characteristic features require special optimizations.

As a result Samsung series The 850 Pro has the following set of features:

Manufacturer	Samsung
Series	850 Pro
Model number	MZ-7KE128	MZ-7KE256	MZ-7KE512	MZ-7KE1T0
Form factor	2.5 inch
Interface	SATA 6Gb / s
Capacity	128 GB	256 GB	512 GB	1 TB
Configuration
Memory chips: type, interface, process technology, manufacturer	Samsung 86Gbps 40nm MLC V-NAND
Memory chips: number / number of NAND devices in a chip	2/4 + 2/2	2/8 + 2/4	4/8 + 4/4	4/16 + 4/8
Controller	Samsung MEX
Buffer: type, volume	LPDDR2-1066, 256 MB	LPDDR2-1066, 512 MB	LPDDR2-1066, 512 MB	LPDDR2-1066, 1 GB
Performance
Max. sustained sequential read speed	550 MB / s	550 MB / s	550 MB / s	550 MB / s
Max. sustained sequential write speed	470 MB / s	520 MB / s	520 MB / s	520 MB / s
Max. random read speed (4 KB blocks)	100,000 IOPS	100,000 IOPS	100,000 IOPS	100,000 IOPS
Max. random write speed (4 KB blocks)	90,000 IOPS	90,000 IOPS	90,000 IOPS	90,000 IOPS
physical characteristics
Power consumption: idle / read-write	0.4W / 3.0-3.3W
Impact resistance	1500 g
MTBF (Mean Time Between Failures)	2.0 million hours
Recording resource	150 TB
Dimensions: LxHxG	100x69.85x6.8 mm
Weight	66 g
Guarantee period	10 years
recommended price	$130	$200	$400	$700

While the performance of the Samsung 850 Pro is held back in large part by its SATA 6Gb / s interface, even simple formal specifications make it possible to experience the power behind the flash drive. Pay attention to the speed characteristics of the younger model with a capacity of 128 GB. This modification practically does not lag behind its older brothers, despite the fact that the controller in it cannot use the alternation of devices in its channels. Typical write speeds for 128 GB SSDs with SATA 6 Gb / s are in the order of 300 MB / s, but the Samsung 850 Pro of the same size produces an almost possible maximum of 470 MB / s. This clearly indicates the significantly higher write speeds provided by V-NAND technology. It looks very likely that when Samsung finally releases a V-NAND-based PCI Express flash drive, it will be a bombshell. However, we still have to live up to this wonderful moment.

The second advantage of V-NAND, clearly seen in the Samsung 850 Pro spec sheet, is its high reliability. All modifications, including the youngest model with a capacity of 128 GB, have a declared write resource at the level of 150 TB, that is, 80 GB per day for a five-year period. And that's not just more than promised for any other consumer SSD model. The manufacturer emphasizes that such a resource was established not for technological, but for political reasons, so that the Samsung 850 Pro does not create internal competition for server models with a higher guaranteed reliability... In fact, the amount of data that can be written to new SSDs with 3D flash memory is measured in petabytes. In other words, the problem of exhaustion of the recording resource during typical desktop use for the Samsung 850 Pro should not be at all. That is why the warranty period has been extended to 10 years.

I would like to note the implementation in the Samsung 850 Pro of a number of technologies that are useful when installing this drive in mobile computers. In particular, this SSD has improved support for the DevSleep state, which allows you to send the drive to sleep mode with a consumption of about 2 mW. The controller also supports temperature monitoring, and when the drive heats up to critical conditions, throttling is automatically turned on.

Implemented in Samsung 850 Pro and hardware encryption using the AES algorithm with a 256-bit key. As with the company's earlier SSDs, the crypto engine is compliant with the Windows eDrive (IEEE 1667) and TCG Opal 2.0 specifications, which means that encryption can be managed from within the operating system, for example via standard remedy BitLocker.

To what has been said, it remains only to add that Samsung belongs to the small number of manufacturers who care about providing users with convenient service utilities. With the Samsung 850 Pro, the Samsung Magician program works great, with a comprehensive set of features, including firmware updates, flash drive health monitoring, operating system optimization, and more.

Separately, it should be said about the implemented in Samsung Magician software technology improving the performance of RAPID, which can be paired with a novelty and allows you to select a part random access memory to cache access to SSD. At the same time, the data exchange rates, of course, increase, but the price for this is the risk of losing information cached in memory in the event of sudden power outages, reboots or system freezes. Simultaneously with the release of the Samsung 850 Pro, the manufacturer updated the RAPID technology to version 2.0, and now it can allocate either 1 GB of memory or 4 GB for the cache, depending on whether more or less 16 GB of RAM is installed in the system.

⇡ Exterior and internal structure

We tested the Samsung 850 Pro with a capacity of 256 GB. In terms of performance, this model, like its 512 GB and 1 TB counterparts, has the highest possible performance.

Externally, the Samsung 850 Pro differs little from previous Samsung flash drives. This SSD uses the exact same 7mm high 2.5-inch chassis as the last flagship model, the 840 Pro. The external color is black, the front surface is painted with the Samsung logo and an orange square, in one form or another present on all SSDs of the company of the same form factor. There is a label on the back of the case, from which you can get information about the name and capacity of the model, its article and serial number.

The insides of the Samsung 850 Pro 256 GB are much more interesting. The first thing that catches the eye is that this SSD is based on a stripped-down PCB. This board contains only six microcircuits.

The first microcircuit is the Samsung MEX controller itself. It should be noted that there are no heat-conducting pads on it, and it does not come into contact with the body. That is, the manufacturer is sure that the heat dissipation of the controller is negligible. A memory chip is installed above the controller. In our case, this is a 512 MB LPDDR2-1067 used as a buffer.

As for the remaining four chips with flash memory, their set turned out to be a little unusual. Since the V-NAND die used in the Samsung 850 Pro is 86 Gbps, the 256GB SSD had to fit two different types of chips: two with four cores and two with eight cores. Thus, the controller addresses 24 cores on eight channels, that is, it uses three-fold interleaving of devices in each channel. However, as we saw from the performance characteristics, this is not a problem and the Samsung 850 Pro 256 GB shows the maximum possible speed under any load conditions.

If you add the 24 86 Gb poisons together, the total flash storage capacity in the Samsung 850 Pro 256 GB is actually 258 GiB. Of these, only the traditional 238.4 GiB is available to the user, and the remaining 7.6 percent of the capacity is allocated to the operation of garbage collection technologies, wear leveling and, probably, to a replacement fund, the need for which for memory with a resource of 35 thousand rewriting cycles raises some doubts.

However, the Samsung 850 Pro printed circuit board does not have any capacitor banks, which means that this SSD does not provide any special means of preserving the integrity of information in the event of a sudden power outage. This is another reason why a consumer drive built on V-NAND with an almost infinite resource cannot be classified as a server solution.

⇡ Testing methodology

Testing is carried out in the operating system Microsoft Windows 8.1 Professional x64 with Update, which correctly recognizes and maintains modern solid-state drives. This means that the TRIM command is supported and actively used during the tests, as in normal day-to-day use of the SSD. Performance is measured with drives in a "used" state by pre-filling them with data. Drives are cleaned and maintained before each test using TRIM commands... There is a 15-minute pause between individual tests, which is allotted for the correct practice of garbage collection technology. All tests, unless otherwise noted, use randomized incompressible data.

Applications and tests used:

• Iometer 1.1.0

1. Measuring the speed of sequential read and write data in blocks of 256 KB (the most typical block size for sequential operations in desktop tasks). The estimation of the speeds is carried out within a minute, after which the average is calculated.
2. Measuring the speed of random read and write in 4 KB blocks (this block size is used in the overwhelming 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 actively working with a branched file system). Data blocks are aligned relative to the flash drive pages. The assessment of the speeds is carried out within three minutes, after which the average is calculated.
3. Determination of the dependence of the random read and write speeds during operation of a drive with 4K blocks on the depth of the request queue (in the range from one to 32 commands). Data blocks are aligned relative to the flash drive pages. The assessment of the speeds is carried out within three minutes, after which the average is calculated.
4. Determination of the dependence of the random read and write speeds when the drive is operating with blocks of different sizes. Blocks from 512 bytes to 256 KB in size are used. The depth of the request queue during the test is 4 commands. Data blocks are aligned relative to the flash drive pages. The assessment of the speeds is carried out within three minutes, after which the average is calculated.
5. Measurement of performance under a mixed multithreaded load and establishing its dependence on the ratio between read and write operations. Sequential operations of reading and writing of 128 KB blocks are used, performed in two independent streams. The ratio between read and write operations varies in 10 percent increments. The assessment of the speeds is carried out within three minutes, after which the average is calculated.
6. Investigation of SSD performance degradation when processing a continuous random write workflow. The blocks are 4 KB and the queue depth is 32 commands. Data blocks are aligned relative to the flash drive pages. The test duration is two hours, instantaneous speed measurements are carried out 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 work of the garbage collection technology and after the TRIM command has been executed.

• CrystalDiskMark 3.0.3 b
  A synthetic benchmark that provides typical performance metrics for solid-state drives as measured on a 1GB disk area “on top” of the file system. Of the entire set of parameters that can be estimated using this utility, we pay attention to the sequential read and write speed, as well as the performance of random reads and writes in 4K blocks without a request queue and with a queue of 32 commands deep.
• PCMark 8 2.0
  A benchmark based on the emulation of a real disk load, which is typical for various popular applications. A single partition is created on the tested drive in the file NTFS system for the entire available volume, and in PCMark 8 the Secondary Storage test is carried out. As test results, both the final performance and the execution speed of individual test traces generated by various applications are taken into account.

⇡ Test stand

A computer with an ASUS Z97-Pro motherboard, a Core i5-4590 processor with an integrated Intel HD Graphics 4600 graphics core and 16 GB DDR3-2133 SDRAM is used as a test platform. SATA drives connect to the SATA 6Gb / s controller built into the motherboard chipset and operate in AHCI mode. The Intel Rapid Storage Technology (RST) driver 13.1.0.1058 is used.

The volume and speed of data transfer in benchmarks are indicated in binary units (1 KB = 1024 bytes).

⇡ Test participants

• Crucial M550 256GB (CT256M550SSD1, firmware MU01)
• Intel SSD 730 480 GB (SSDSC2BP480G4, firmware L2010400);
• OCZ Vector 150 240 GB (VTR150-25SAT3-240G, firmware 1.2);
• Plextor M5 Pro Xtreme 256 GB (PX-256M5P, firmware 1.07);
• Samsung 840 Pro 256 GB (MZ-7PD256, firmware DXM06B0Q);
• Samsung 850 Pro 256 GB (MZ-7KE256, firmware EXM01B6Q);
• SanDisk Extreme II 240GB (SDSSDXP-240G, firmware R1311).

⇡ Performance

Sequential read and write operations, IOMeter

As promised by the specs, the sequential operations of the Samsung 850 Pro are limited by the SATA 6Gb / s bandwidth. In other words, here we do not have the opportunity to find out how productive the Samsung platform built on V-NAND is, but in any case, you will not find a faster sequential reading or writing of a solid-state drive with a SATA interface.

⇡ Random read and write operations, IOMeter

But in case of random reading, the power of the new Samsung flash drive can be clearly seen. We are indeed dealing with a consumer SSD offering the highest performance to date. And although the above couple of graphs only refer to random read operations, this conclusion can be transferred to most of the disk activity inherent in personal computers. It is the operations of random reads with a low depth of the request queue that make up the bulk of the load that falls on modern disks, and the Samsung 850 Pro, as we can see, is perfectly "sharpened" for it.

With random write operations, the picture is not so unambiguous. In the absence of a request queue, the Samsung 850 Pro unexpectedly falls short of the OCZ Vector 150 and Crucial M550. However, the increase in queue depth is returning everything to its place, and the Samsung 850 Pro again occupies the top line in the chart.

Let's now take a look at how the performance of the Samsung 850 Pro depends on the depth of the request queue when working with 4K blocks.

When reading with varying queue depths, the Samsung 850 Pro is by far the best SATA 6Gb / s drive on the market. When recording with a queue of 1 or 2 commands, it is still slightly inferior to the Crucial M550 and OCZ Vector 150. However, to say that the new Samsung product is not fast enough, the language does not turn around here either.

The next pair of graphs shows the dependence of the performance of random operations on the size of the data block.

The Samsung 850 Pro works equally well with blocks of any length for any operation. In both cases, the line showing its performance, as it were, borders the indicators of other drives on top. And this means that there is not a single block size option on which the SSD under consideration would not demonstrate the best result.

Mixed Load Testing is a new addition to our SSD testing methodology. As the cost becomes cheaper, solid-state drives are no longer used as exclusively system drives and become ordinary scratch disks. In such situations, not only the refined load in the form of writing or reading falls on the SSD, but also mixed requests, when read and write operations are initiated by different applications and arrive at the same time.

However, full duplex operation for modern SSD controllers remains a significant challenge. Mixing reads and writes in the same queue slows down the speed of most consumer-grade SSDs. This was the reason for a separate study in which we are testing how SSDs perform when it is necessary to handle mixed sequential operations. The following diagram shows the most common case for desktops, when the ratio of the number of reads and writes is 4 to 1.

As follows from the above diagram, despite their three-core structure, Samsung controllers have not yet learned how to effectively work with mixed read and write operations. If a second stream initiating writing is mixed with sequential reading, then the speed of the Samsung 850 Pro drops below the level set by the Crucial M550 and OCZ Vector 150. In other words, the mixed load puts the new Samsung product, which demonstrates simply outstanding results in most tests, in a disadvantageous position ...

The following graph gives a more detailed picture of performance under a mixed load, showing the dependence of the speed of an SSD on the ratio of read and write operations to it.

The more read and write operations are mixed, the lower the performance of the Samsung 850 Pro is. The corresponding curve for this flash drive is clearly U-shaped, which indicates that the Samsung MEX controller is poorly optimized for full duplex operation. However, this behavior is the scourge of almost any modern solid-state drives for personal computers, except perhaps the OCZ Vector 150. However, the drop in performance of the Samsung 850 Pro on mixed operations reaches twice the size, which is slightly more than that of other flagship SSDs.

⇡ Degradation and recovery of performance

Observing the change in the write speed depending on the amount of information recorded on the disk is a very important experiment that allows you to understand the work of the internal algorithms of the drive. In this test, we load the SSD with a continuous stream of requests to randomly write 4K blocks and, along the way, monitor the performance that is observed. In the graph below, the dots represent the instantaneous performance measurements that we capture every second, and the black line shows the average speed observed over a 30-second interval.

As a result of the experiment, we got such an exemplary graph. Until it fills up to full capacity, the Samsung 850 Pro demonstrates a consistent and high write speed, then performance begins to decline. However, the degree of performance drop is not too high, at first the speed decreases from 90 to only 70 thousand IOPS and only then smoothly approaches the asymptote, which lies in the region of 13 thousand IOPS. This means that even in the used state, the Samsung 850 Pro performs better than other consumer SSDs, the write speed of which sags much more. A good illustration of this is the fact that during our 2-hour endurance test, we were able to record a total of 867 GB of data on the Samsung 850 Pro with 256GB. When conducting a similar test with other flagship flash drives of the same capacity, the amount of recorded information is usually about 700-720 GB.

Noteworthy is how well the Samsung 850 Pro maintains the constant write speed. Even after filling once, the scatter is almost invisible, which means the Samsung 850 Pro will fit perfectly in applications where performance consistency is required.

However, everything that is shown in the graph above is mostly an artificial situation, interesting only for studying the features of the controller, but not illustrating the behavior of an SSD in real life in a personal computer. What is really important is how, after such a degradation, performance is restored to its original values. To investigate this issue, after completing the test leading to degradation of the write speed, we wait 15 minutes, during which the SSD can try to recover by itself due to garbage collection, but without the help of the operating system and the TRIM command, and measure the speed. Then the TRIM command is forcibly sent to the drive - and the speed is measured again.

CrystalDiskMark is a popular and simple benchmarking application that runs on top of the file system and delivers results that are easily repeatable by ordinary users. And what this benchmark gives out, from a qualitative point of view, almost does not differ from the indicators that were obtained by us in the heavy and multifunctional IOmeter package. Under almost all load conditions, the Samsung 850 Pro is among the leaders, and on random read operations without a queue of requests, its performance is even noticeably higher than that of other flagship SSDs from other companies. There is only one exception - random recording without a queue of requests: here Samsung 850 Pro loses to OCZ Vector 150 and Crucial M550. However, this failure of the flash drive in question should hardly be taken to heart - such a load during typical desktop use occurs very, very rarely.

⇡ PCMark 8 2.0 Real-World Use Cases

The Futuremark PCMark 8 2.0 test suite is interesting in that it is not synthetic in nature, but rather based on how real applications work. In the course of its passage, real scenarios of disk usage in common desktop tasks are reproduced and the speed of their execution is measured. The current version of this test simulates a load taken from real gaming applications Battlefield 3 and World of Warcraft and software packages from Abobe and Microsoft: After Effects, Illustrator, InDesign, Photoshop, Excel, PowerPoint and Word. The final result is calculated in the form of the average speed shown by drives when passing test tracks.

Performance in PCMark 8 is one of the critical parameters to understand how good a particular drive is in real use... And if we rely on the indicators obtained here, then the conclusion suggests itself that the Samsung 850 Pro, which amazed us with the highest results in various synthetic tests, in real work in applications turns out to be not at all as fast SSD as it seemed at first. It is not only outperformed by the high-speed 480GB version of the Intel 730, but also inferior to its predecessor, the Samsung 840 Pro. To be honest, this state of affairs seems somewhat unnatural and inconsistent with the rest of the tests. Therefore, there is a suspicion that the problem lies, for example, in some unsuccessful software optimizations that can be fixed in future firmware versions.

However, the integral result of PCMark 8 must be supplemented with the performance indicators given by flash drives when passing separate test tracks, which simulate various variants of real load. The point is that the tested flash drives behave slightly differently under different loads.

It turns out that the Samsung 850 Pro has several problematic applications at once, the results in which pull the overall PCMark 8 score down. It - Microsoft Word, Battlefield 3, Adobe photoshop when working with "heavy" images, Adobe Illustrator and Adobe AfterEffects. The listed applications are characterized by the fact that the load in them is clearly heterogeneous with predominant read operations, but the write operations mixed in with them seriously reduce the read speed. We saw a similar situation in tests of mixed load, and here it manifested itself in the results of a test based on real problems.

⇡ Endurance testing

The results of testing the endurance of the drive in question are given in a separate special material "Resource tests of the SSD".

⇡ Conclusions

Recently, each new Samsung SSD has been a small revolution. The company consistently introduces fundamentally new technologies and increases the productivity of its own solutions, offering more and more every time. And the Samsung 850 Pro is no exception: in fact, it turns out to be the best SATA 6Gb / s drive we've seen.

However, we cannot announce that the novelty has brought the performance of consumer SSDs to some new level. In fact, the advantage it provides is purely formal. But the Koreans are not to blame, the performance of the Samsung 850 Pro is clearly limited by the interface's capabilities. The fact that a lot of power is hidden inside it can be seen only by the speed of random reading in 4-kilobyte blocks, at which the advantage of the new item over other flagship SSDs is about 6-7 percent.

However, despite the ephemeral superiority of the new model over other flagship flash drives, Samsung did not hesitate to set frankly inflated prices on its new SSD. Modern budget SSDs like the Crucial MX100 cost almost half today. Of course, the Samsung 850 Pro has a 10-year warranty, a huge recording resource, almost eternal flash memory and an excellent package bundle. software but is it all worth the overpayment? Doubtful.

It turns out that the Samsung 850 Pro is not a mass product at all, but an elite offer for uncompromising enthusiasts that can fit well into a Haswell-E-based system equipped with video cards like the GeForce Titan Z, but nothing more. If we are talking about a complete set, a standard desktop or mobile system, then instead of the Samsung 850 Pro, it is easy to find more attractive options in terms of price-performance ratio, which are only slightly inferior in operating speed.

As a result, the Samsung 850 Pro is of greatest interest not from a practical, but from a technological point of view, because this is the first solid-state drive in which three-dimensional flash memory has found application, which should become a ubiquitous solution over the next few years. In theory, such memory can significantly increase the speed of work and significantly reduce the cost of an SSD, but so far both of these possibilities have remained unrealized. Performance hit the SATA 6Gb / s bandwidth, and the price was high because the Samsung 850 Pro is just a pilot. That is, it is still very difficult to evaluate V-NAND at its true worth, but Samsung was able to intrigue us... And now we are looking forward to the appearance of the next SSDs from this manufacturer, built on the same memory, but at least transferred to the PCI Express bus.

At the beginning of this year, we planned a small update of the test method, but it was decided to postpone it a little so that we could compare three more interesting drives with all previously studied ones. What's so interesting about them? First of all - the manufacturer and its history.

Unlike many other companies operating in this market, Samsung was at its origins (so to speak), and it has always been "interested" in high-end devices. In particular, it was Samsung 64 GB SSD SATA-2 that about ten years ago was one of the few competitors to Intel X25-M at the time of the release of the latter, and in a number of scenarios it remained unsurpassed then. Of course, this did not save him: as with all "first generation" devices, high speed characteristics were achieved thanks to the use of fast, but very expensive SLC memory. The X25-M, on the other hand, demonstrated another way of improving performance: combining [relatively] inexpensive MLC flash with an intelligent controller. The end result is a fast $ 600 device for 80GB - to which Samsung and others could only respond with a 64GB model for $ 1000.

The company made the right conclusions, immediately starting to develop controllers. At first, they were sold to many manufacturers, but there were not enough stars from the sky. On the other hand, this made it possible to accumulate the necessary experience and finally determine the directions for further development. Two major decisions were made: first, to sell the storage business for hard magnetic disks (so as not to interfere), and secondly, to produce solid-state drives entirely of our own design, and without giving the components "to the side". The first at that time seemed a bold, but risky step: after all, hard drives had a very stable demand due to prices, so that flash memory could not compete with them directly. However, with t. Z. It was logical for the largest semiconductor manufacturer to just work to make it possible :) That the company did in subsequent years, especially having such a serious trump card in its sleeve as independent production of everything necessary, as well as the first place in terms of production of flash memory. As a result, controllers could always be “fitted” to memory, and memory - to controllers, and Samsung was much less dependent on market conditions than most manufacturers - rather, the company determined it. Many promising directions were also correctly calculated in advance. In particular, more than four years ago we already got acquainted with - in fact, the second attempt of the company (the first was the "regular" 840) to create a fast and reliable drive based on TLC memory, which no one used for this then. I didn't even try. It cannot be said that there were no rough edges at all, but valuable experience was accumulated. In particular, the SLC caching technology was tested at the same time.

It would seem that there is something special about it? Now TLC memory is already familiar - everyone uses it. And SLC cache too. But that was, recall, in 2013. And around the same time, Samsung decided to tackle "3D" flash memory, as the traditional approach of keeping "regular" cells and reducing production rates began to gradually come to a standstill. However, all manufacturers started talking about the transition to 3D NAND in those years, since everyone was in a similar position. But from conversations to implementation, a lot of time always passes - someone overcomes this path faster, someone more slowly. Samsung managed to get ahead of everyone: in mid-2014, the first commercial products using V-NAND (as the developer called it) appeared. At first, the company configured this memory exclusively as MLC, to work in a more sparing mode, but since 2015, the number of crystals that can work reliably and with eight levels has begun to increase, which allows you to store three bits of information. Note, by the way, that Samsung prefers not to use the abbreviation "TLC" when speaking of "3-bit MLC". In principle, this is quite correct, although it can be confusing for some. But for most buyers it is important, after all, not what is called, but how it works. And today we will study this on the example of three Samsung products - two completely new and one also almost new.

Samsung V-NAND SSD 850 Evo 500GB

The first drives of the line with this name appeared, as already mentioned, in 2015. In principle, they were very similar to the 840 Evo, but instead of planar 128 Gbit crystals they used 32-layer 3D of the same capacity. The assortment has slightly thinned: 120/250/500/1000 GB - without an interesting intermediate model with a capacity of 750 GB. The older model even retained the same three-core MEX controller as in the 840 Evo, while the others received dual-core, but improved MGX, paired with LPDDR2 memory with a frequency of 1066 MHz and a capacity of up to 1 GB. At the same time, the drive (like its predecessor) was positioned as a competitor to mid-range devices - at that time, mainly using MLC memory. However, even those often had only a three- and not five-year warranty, which has become the hallmark of the Evo family. Including the 2 TB modification that appeared a little later - which at that time was a very serious value, so it required the appearance of a special MHX controller (at the same time, the DRAM cache in this model was transferred to a faster LPDDR3 memory).

Significantly surpassed in the second generation 850 Evo, which already used 48-layer 3D NAND with 256 Gb crystals. In principle, this, and all other things being equal, would make it possible to transform the lineup from "120/250/500/1000/2000 GB" to "250/500/1000/2000/4000 GB", which was done, but the company did not limit itself to other equals. Transferring, for example, DRAM cache from LPDDR2 to LPDDR3 in the entire line, etc. However, these improvements were mostly cosmetic and did not affect performance too much. And it was not required - a streamlined production process allowed the release of fast and reliable memory, while competitors were still taking only the first steps along the way.

And at the end of last year, the company once again updated the 850 Evo - since production had already been switched to 64-layer memory: more cost-effective. There are no fundamental changes between the models, so, like the previous "upgrade", this one went quietly: just from a certain moment, supplies of old-style drives stopped and only new ones began to be shipped. Some differences in terms of modifications could be looked for - in particular, devices with a capacity of 1 TB or more began to use 512 Gb crystals, but 256 Gbps remained in 250 and 500 GB to keep the performance characteristics at the same level. And cache memory of the LPDDR3 type on the basis of "megabytes per gigabyte of capacity." The guarantee, of course, remained a five-year limited TBW according to the formula "75 TB for every 250 GB", that is, 150 TB for our hero.

The main thing for the buyer in general in all these evolutionary changes was the constant price decline. Other manufacturers, as a rule, achieved a similar effect by releasing new models - Samsung preferred to modify the existing one. As a result, the 850 Evo at the end of its life cycle is not at all the same 850 Evo as at the beginning. In 2015, these drives did not try to compete in price with the cheapest SSDs on the market - for this, Samsung sometimes released planar TLC devices, such as the 750 Evo or 650. In 2017, they could already. At the same time, their speed characteristics at least did not decrease - the introduction of TLC memory in the products of other companies, as we have noted more than once, was usually accompanied by a decrease in performance and reliability. However, three years is a long period: during this time, both controller manufacturers and 3D NAND from other suppliers have "pulled up". To which Samsung has prepared not even one, but two answers.

Samsung V-NAND SSD 860 Evo 500 GB

Just a few months after the last "upgrade" 850 Evo, the company released new line drives - on the same memory. Almost on the same: in models from 1 TB, nothing has changed, and the 500 GB modification (which we will test today) received 512 Gbps crystals similar to the older ones, instead of 256 Gbps. Thus, in some conditions, it may lag behind its predecessor, which can be considered a disadvantage. But quite predictable: 500 GB now no longer evokes any reverence, gradually turning into a running volume, at a price already available to many users. Why do you need to reduce the cost - even at the cost of reducing some speed characteristics.

Since this will not always happen: the new series of drives also received a new MJX controller. It remains dual-core, but the clock frequency has almost doubled, which allows working with more complex algorithms. In particular, the SLC cache has changed for the first time in many years (since its appearance in the 840 Evo!). Previously, it was static, but now, if necessary and there are free cells, the new controller can use some of them in SLC mode, postponing the data “compression” “for later” - when the load decreases. In practice, this means that if the 840 Evo and all versions of the 850 Evo with 500 GB could accept only 6 GB of data at high speed (static SLC cache, 3 GB in size for every 250 GB of capacity), then in a similar 860 Evo the limit is increased already up to 22 GB. In principle, the latest Silicon Motion controllers (such as SM2258 or SM2259) can write at least all free cells in SLC mode (i.e., up to a third of the total device capacity), but in practice, the first value is sufficient. Strictly speaking, for the majority of users who are not fond of "hunting for parrots" in benchmarks, 6 GB was more than enough, but since competitors have appeared, it is necessary to somehow answer this.

In principle, an increase in TBW to maintain warranty conditions can also be considered a response to external influences. For example, those that appeared last year have a five-year warranty, but limited to 72 TB for every 128 GB of storage. The 850 Evo, we recall, is 75 TB by 250 GB, that is, almost half the size. And in the 860 Evo, it's already a little more, since the previous value has been doubled: 150 TB for every 250 GB. In general, no one bothered the company to do this before. And not only because the drives are physically capable of this - just when they are used "as intended" in ordinary personal computers, the recording volumes are much more modest. Why do manufacturers limit them? To protect a little from the rather popular "misuse" - when consumer drives with a long warranty are installed somewhere in the server: there are backups, but "will be covered" - they will be changed. Naturally, this reduces the sales of devices for the corresponding purpose, which is absolutely unnecessary for their main suppliers (and Samsung is one of them). Especially considering the availability of one more product in the assortment ...

Samsung V-NAND SSD 860 Pro 512GB

The release in 2018 in a new line of a SATA drive based on MLC memory is, of course, a very bold decision, but quite justified. In any case, if we abstract only from requests spherical pc users in vacuum, but to look at the market more broadly. After which we will immediately see, for example ... various network storages. NVMe devices are not needed there. Until recently, it was believed that SSDs are not needed at all, since they are too expensive, and performance is not determined by them. When using gigabit network adapters and with a small number of concurrent requests, this is indeed the case. And a dozen or two users can immediately work with some corporate storage, and a 10 Gbps channel can be used to connect it to the switch - and here the hard drives will be a bottleneck, which we are in the process of testing top NAS repeatedly watched. And solid state drives won't. Of course, they will cost more, but if a problem can be solved for money, then this is no longer a problem, but just costs:) In principle, a device based on TLC memory is suitable for such work, but MLC will provide more stable speed characteristics, and the resource too.

More interesting in this case is the issue of used memory. The previous MLC line of the company, namely the 850 Pro series drives, used 3D TLC NAND rejection - which is the reason for the slightly atypical crystal size at the start: 86 Gbps. The words "rejection", of course, should not be intimidated: it is obvious that the mode of operation of cells with four levels is much more gentle than with eight, and not only faster. The new drives use 64-layer MLC 3D NAND crystals with a capacity of 256 Gbps. With TLC, this does not "beat" in any way, so we can assume that Samsung makes such a memory on purpose. On the other hand (which is more likely, given that it is already 2018), this may also be a by-product of the work on mastering the release of crystals QLC 512 Gb 3D NAND. It is clear that the release of high-quality memory of this type is very difficult, but it still needs to be dealt with. And then what was said above works - having its own production (and the largest in terms of volume), Samsung does not depend on the market situation. If the company needed to buy memory from the open market, launching an SSD on the MLC would be extremely risky. With our own production - no. Especially if these are really those chips that are unable to store four bits per cell - you still need to put them somewhere. And buyers in the end can purchase a device with a large resource - TBW for models of 1 TB and above is just right to call PBW, since the account there goes to petabytes, which is a little unusual for user-purpose drives. Actually, for 512 GB we are talking about 600 TB for a five-year warranty period - versus 300 and 150 TB, respectively, for the 860/860 Evo. But not cheap, of course. But, at least, there is a corresponding offer in the company's assortment, which can be used - if necessary, or simply if desired (and financial opportunity).

Competitors

For comparison, we decided to take the results of two drives: and, fortunately, both are relevant at the moment and use a similar (in the first approximation) memory. 545s also has a five-year warranty in common with our heroes, and the limitations of its conditions are similar to the 860 Evo (however, who stood on whom the question is difficult, as mentioned above). Until recently, Blue 3D had a three-year warranty, but now the company has begun a procedure to increase it to the same five years. However, even under the "old" conditions, it is possible to compare Blue 3D with other participants - this is also a drive from a large and renowned manufacturer, and prices are close.

Testing

Testing technique

The technique is described in detail in a separate article... There you can get acquainted with the used hardware and software.

Application performance

As you would expect, in terms of high-level benchmarks, everyone is pretty much the same. But not really - if you arm yourself with a magnifying glass, you can see that the Samsung SSD triplet is slightly faster than the offerings of Intel and WD. And the distribution of seats inside it is also predictable: the fastest is the 860 Pro, and the slowest is the 860 Evo. However, to notice this, you no longer need a magnifying glass, but a microscope :)

As for potential possibilities of storage devices, the overall picture has not changed - except that the gap from the "pursuers" has increased. Eventually modern versions Evo are the first SATA drives on TLC memory that came into our hands, capable of exceeding 300 MB / s in this test. However, regardless of its type, only one device capable of this has previously been in our laboratory - Toshiba Q300 Pro 256 GB. Thus, the only thing that somewhat overshadows the significance of the event is potentiality this result.

The previous version of the test suite shows us a similar picture. In general, Samsung drives are more favorable than the other way around. That is, it is clear that if the difference in speed is noticeable only in tests, it can be neglected - but why not choose a faster drive, other things being equal. In case of unequal, it is already necessary to choose: which is more important.

Sequential operations

With these scenarios, with a limited data area, everything is clear for a long time - the SATA interface itself is the limiter for SATA drives. Including when writing, since SLC caching has long become the standard behavior of TLC-based drives, and no tricks are needed for MLC memory by themselves. Therefore, in the updated test method, we will complicate the task :) And today we will simply postpone the final verdict until more serious loads.

Random access

Samsung controllers have long been able to cope with such loads easily and naturally, 3D NAND of its own production has never differed in slowness either - as a result, the results are high. Unless the loss of the 860 Evo to its predecessor of the same capacity may upset someone, but there is nothing unexpected in it - an increase in the capacity of crystals and a decrease in their number should have worked. In the end, the performance margin was sufficient to keep ahead of drives of the same class from other manufacturers, even after its decline, and "in-house" competition is still not planned: as old stocks run out, the 850 Evo will simply disappear from the shelves. ...

Working with large files

Reading data, as has been repeatedly said, has not been a problem for memory of any type for a long time (here controllers can limit performance), so everyone rested on the interface at a comparable level.

Writing obviously "flies out" for the capacity of the SLC-cache, despite the increase in its capacity by 860 Evo, and the performance of the memory array itself has decreased due to the decrease in parallelism. Accordingly, if the 850 Evo produced the maximum for the SATA600, then its replacement cannot. And it even lags behind competitors using 256 Gbps crystals in models of this capacity, "holding" larger ones for larger capacities.

Another tricky (so far) scenario for TLC drives is writing and reading. However, for obvious reasons, this problem does not concern the 860 Pro - the use of two-bit cells paired with a high-performance controller allows the device to demonstrate the maximum performance available for SATA600. But the drives of the Evo family are noticeably slower - especially with (pseudo) random access. However, it is also easy to notice that a noticeably higher performance can be ensured only due to tricks, such as an "infinite" SLC cache of drives based on the latest Silicon Motion controllers, but not using conventional static caching. Yes, and "unusual" as in the 860 Evo too - it copes only with less information. However, all this becomes insignificant if we remember that most solid-state drives are not doing better :) But, at the same time, their manufacturers do not leave such a choice as Samsung (which has updated the MLC-line - albeit at an appropriate price).

Ratings

As mentioned above, the performance of the 860 Evo could have been reduced - anyway, "in parrots" it is longer than the main competitors. And if you need even more "birds", it is customary to hunt for them in other places - equipped with different interfaces, in any case. The latter has long been defining a lot - why we immediately wrote that the 860 Pro is primarily not about speed. In any case, not about the one that is interesting to the individual PC user.

But, of course, the representatives of this line will perfectly cope with such loads - they are simply redundant for this. As well as the warranty resource, too, from a completely different area, but especially suspicious buyers can come in handy. And from a performance standpoint, the Evo is good enough. Including the new series - where such has slightly decreased, but still remained significantly higher than that of most competing developments. In any case, within the class - it is clear that changing the interface allows you to remove some bottlenecks (at least in terms of low-level characteristics), but that's another story.

Prices

The table below shows the average retail prices of SSDs tested today, as of the time you read this article:

Intel 545s 512GB	Samsung 850 Evo 500GB	Samsung 860 Evo 500 GB	Samsung 860 Pro 512GB	WD Blue 3D 500GB

Total

In principle, we did not expect any discoveries: Samsung, as already mentioned at the beginning, has solid experience in both the development of solid-state drives in general and the use (and production, which is especially important) of 3D NAND TLC. In fact, the company simply overtook its competitors "at the bend": everyone was talking about the need to switch to 3D NAND, but the transition itself was very difficult for the majority. The resulting head start in a couple of years was handled in the right way by Samsung, as a result of which the company's solutions based on TLC memory are now among the best on the market. And it is very important that by now they can even be considered inexpensive: from the "middle" class, the Evo line has gradually descended into the budget one, without losing its advantages along the way.

At the same time, high production volumes allow the company not to completely abandon MLC NAND. Of course, this memory has already turned into niche solution but niche she definitely has. And with further price reductions, it will only expand. And of course, the 860 Pro will be relatively popular with regular users as well, as some of them are still wary of TLC memory. It is clear that they will have to pay extra for psychological comfort ... But on the other hand, what else is worth paying for if not for comfort? :)

This is the situation today. What will happen tomorrow is unknown. In the semiconductor market, you certainly need to run to just stay in place, and to get somewhere, you need to run twice as fast. In the near future, new "turns" await us in the form of the introduction of QLC NAND, or even "non-NAND" memory at all. And which of the manufacturers will cope with the transition in the best possible way, only time will tell. In the meantime, no one seriously threatens Samsung's position in the SSD market, and the new lines of drives fully and completely confirm this.