Review and testing of ASUS HYPER EXPRESS SSD with SATA Express interface. Installing an SSD in a laptop. Ssd disk connection interfaces release with pci express connection interface

The different types of keys are marked on or near the end pins (gold-plated) of an M.2 SSD, and on the M.2 connector.

The figure below shows the M.2 SSD keys on an M.2 SSD and compatible M.2 slots with slots to allow drives to be inserted into the appropriate slots:

Note that M.2 B-key SSDs have a different number of end pins (6) compared to M.2 M-key SSDs (5); this asymmetric layout avoids the error of placing an M.2 SSD with a B key into an M slot, and vice versa.


What do the different keys mean?

M.2 SSDs with key B terminators may support SATA and/or PCIe depending on the device, but are limited to PCIe x2 (1000MB/s) speeds on the PCIe bus.

M.2 SSDs with M key end pins may support SATA and/or PCIe protocol depending on the device and support PCIe x4 (2000MB/s) speed on the PCIe bus if the host system also supports x4 mode.

M.2 SSDs with B+M key end pins may support SATA and/or PCIe depending on the device, but are limited to x2 speed on the PCIe bus.

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Which M.2 configurations and connectors are not compatible?



SSD M.2 Key B Key M Key
SSD edge connector - B Key SSD edge connector - M Key
Incompatible Sockets Not Compatible Sockets - B Key Not Compatible Sockets - M Key

What are the benefits of having a B+M key on an M.2 SSD?

B+M keys on M.2 SSDs provide cross compatibility with various motherboards as well as support for the appropriate SSD protocol (SATA or PCIe). Some motherboard host connectors may be designed to accept only M-keyed SSDs or only B-keyed SSDs. B+M-keyed SSDs are designed to address this issue; however, plugging an M.2 SSD into the socket does not guarantee it will work, it depends on the common protocol between the M.2 SSD and the motherboard.


What types of M.2 SSD host connectors are found on motherboards?

M.2 host connectors can be either B-key or M-key based. They can support both the SATA protocol and the PCIe protocol. Conversely, they can only support one of the two protocols.

If the SSD end pins are B+M keyed, they will physically fit into any host connector, but you should check your motherboard/system manufacturer's specification to ensure protocol compatibility.


How can I find out what length of M.2 SSD my motherboard supports?

You should always check your motherboard/system manufacturer's information to verify supported card lengths, however most motherboards support 2260, 2280, and 22110. Many motherboards have a movable retention screw, allowing the user to install an M.2 2242, 2260, 2280, or even 22100 SSD . The amount of space on the system board limits the size of the M.2 SSDs that can be installed in the socket and used.


What does "socket 1, 2 or 3" mean?

Different connector types are part of the specification and are used to support specific types of devices in a connector.

Socket 1 is for Wi-Fi, Bluetooth®, NFC and WI Gig

Socket 2 is for WWAN, SSD (cache) and GNSS

Socket 3 dedicated to SSD (SATA and PCIe, up to x4 speed)


Does socket 2 support both WWAN and SSD?

If your system has and is not using Socket 2 to support a WWAN card, it can be used for an M.2 SSD (usually a compact form factor like 2242) if it has a B key. An M.2 SATA SSD can be inserted into compatible WWAN connectors if the motherboard supports it. Usually low capacity M.2 2242 SSDs are used for caching along with a 2.5" hard drive. In any case, you should consult the system documentation to verify M.2 support.


Is it possible to hot-plug an M.2 SSD?

No, M.2 SSDs are not meant to be hot plugged. Installing and removing an M.2 SSD is only allowed when the system is powered off.


What are single-sided and double-sided M.2 SSDs?

For some embedded systems with limited space, the M.2 specifications provide for different thicknesses of M.2 SSDs - 3 single-sided versions (S1, S2 and S3) and 5 double-sided versions (D1, D2, D3, D4 and D5). Some platforms may have specific requirements due to space limitations under the M.2 connector, see figure below (Proprietary of LSI).


Kingston SSDM.2 conforms to M.2 double-sided specifications and can be installed in most motherboards that are compatible with double-sided M.2 SSDs; Please contact your sales representative if you require single-sided embedded SSDs.


What is planned for the future?

The next generation M.2 PCIe SSDs will move from using the old AHCI drivers now built into operating systems to a new architecture using the new Non-Volatile Memory Express (NVMe) host interface. NVMe was designed from the start to support NAND-based SSDs (and possibly newer non-volatile memory) and delivers even higher levels of performance. Pre-production testing shows that its speeds are 4 to 6 times faster than today's SATA 3.0 SSDs.

It is expected that it will begin to be implemented in 2015 in the corporate sphere, and then transferred to client systems. As the industry prepares the ecosystem for the release of NVMe SSDs, beta drivers already exist for many operating systems.

While desktop hard drives have been around for years in the 3.5-inch form factor, SSDs have been in the 2.5-inch format since the beginning. It was great for small SSD components. However, laptops were getting thinner, and 2.5-inch SSDs no longer met the criterion of small size. Therefore, many manufacturers have turned their attention to other form factors with smaller dimensions.

In particular, the mSATA standard was developed, but it appeared too late. The corresponding interface is quite rare today, in no small part because mSATA (short for mini-SATA) still operates at the comparatively slow speed of SATA. mSATA drives are physically identical to Mini PCI Express modules, but mSATA and mini PCIe are not electrically compatible. If the socket is for mSATA drives, you will only be able to use them. Conversely, if the socket is for mini PCI Express modules, mSATA SSDs can be inserted but will not work.

The mSATA standard can be considered obsolete today. It gave way to the M.2 standard, which was originally called the Next Generation Form Factor (NGFF). The M.2 standard gives manufacturers more flexibility in terms of SSD dimensions, since the drives are much more compact, eight lengths are allowed, from 16 to 110 mm. M.2 also supports different interface options. Today, the PCI Express interface is increasingly used, which will dominate in the future, because it works much faster. But the first M.2 drives relied on the SATA interface, and USB 3.0 is theoretically possible. However, not all M.2 slots support all of the interfaces mentioned. Therefore, before buying a drive, check which standards your M.2 slot supports.

The M.2 standard is now spreading among desktop PCs, modern motherboards offer at least one corresponding slot. Another positive point is that the cable is no longer required, the drive is inserted directly into the motherboard slot. However, connection via cable is also possible. But for this, the motherboard must have an appropriate port, namely U.2. Previously, this standard was known as SFF 8639. Of course, it is theoretically possible to equip 2.5-inch drives with a U.2 port, but there are very few such models on the market, as well as drives with SATA Express.

The SATA Express interface is the successor to SATA 6Gb/s and is therefore backwards compatible. In fact, the host interface even supports two SATA 6 Gb / s ports or one SATA Express. This support was added more for compatibility as SATA Express drives are electrically connected to the PCI Express bus. That is, SATA Express drives on "clean" SATA 6 Gb / s ports do not work. But SATA Express only relies on two PCIe lanes, which means the throughput will be half that of M.2.

Compact and very fast: M.2 SSDs with PCI Express interface, photo with adapter card

Of course, most desktops have regular PCI Express slots, so you can install an SSD directly into a slot such as a graphics card. You can purchase an adapter card for M.2 SSD (PCIe), and then connect the drives in the "traditional" way in the form of a PCI Express expansion card.

M.2 SSDs with PCI Express interface show throughput of more than two gigabytes per second - but only with the right connection. Modern M.2 SSDs are usually designed for four lanes of third generation PCI Express, only this interface allows you to unlock their performance potential. With the old PCIe 2.0 standard and/or fewer lanes, SSD drives will work, but you will lose a very significant amount of performance. When in doubt, we recommend looking at the motherboard user manual for the M.2 line configuration.

If the motherboard does not have an M.2 slot, you can install one via an expansion card, for example, in a slot for a second video card. However, in this case, most often, not 16, but 8 PCI Express lanes will be supplied to the video card. However, this will not affect the performance of the video card so seriously. The following table summarizes the modern interfaces:

Current development trends are such that the PCI Express bus should soon replace the SATA 6 Gb / s interface everywhere - this is already included in the SATA 3.2 specification version. Further development of SATA suggests that desktop SSDs will retain their usual design, but will be connected via a special SATA Express interface, which will introduce a new type of connectors and cables. At the same time, SATA Express combines two SATA 6 Gb / s interfaces (they are needed for backward compatibility with older drives) and several PCI Express lanes. The first generation SATA Express ports that may currently be present on motherboards based on the Intel Z97 logic set (Fig. 1) involve the use of two second generation PCI Express lanes, which means that the peak throughput of the current implementation of SATA Express increases to 1 GB / s .

The second option provided by the specification for connecting drives via the PCI Express bus is specialized M.2 slots (also known as NGFF), primarily aimed at mobile applications. These slots, which are relatively small and therefore ideal for thin and ultra-thin laptops, combine one SATA 6 Gb / s interface and several PCI Express lanes. In the first version, which is now widely used on motherboards based on ninth-generation Intel chipsets, again, two PCI Express 2.0 lanes are used. In other words, M.2 slots can be viewed as a simple mobile adaptation of the SATA Express interface.

Rice. 1. Updated Intel Rapid Storage Technology, supports M.2 and SATA Express PCIe drives (enables Intel® Rapid Storage Technology features with PCI Express* based SSDs).

In fact, SATA Express and M.2 are designed to solve the same problem - connecting high-speed drives via the PCI Express interface, for which SATA performance is no longer sufficient. However, the architecture of these interfaces is noticeably different.

SATA Express is designed with two standard SATA 3.0 ports and an additional four-pin connector - all combined into one connector. It is designed for drives used in conventional PCs; either two SATA drives or one high-speed SSD with PCI Express x2 interface can be connected to it, respectively. It is worth recalling that the SATA port has 7 pins, and for the operation of one PCI Express channel, 9 pins are required. Hence the need for an additional four-pin connector - two PCI Express lines need 18 pins, and this is exactly what the SATA Express connector provides: 7 + 7 + 4. Obviously, a special cable is required to use PCI Express x2. But there are no power lines in the PCI Express interface. The bandwidth of PCI Express x2 is 16 Gb / s - this is more than the total performance of two SATA 3.0 channels (12 Gb / s) and is more than enough for even the most modern and fast SSD. By the way, at the moment, drives with PCI Express interface are still exotic and inaccessible to the mass user.

Another thing is M.2 - serial devices with this interface have already been released enough. But if SATA Express is aimed at desktop PCs and allows you to connect traditional SSDs and hard drives, then M.2 is designed for use in mobile devices such as laptops and tablets, along with drives made in the form of an expansion board and inserted directly into the connector. Like SATA Express, the M.2 interface provides backward compatibility with SATA, but since more than one device cannot be physically connected to it at the same time, only one SATA 3.0 channel is provided. But this made it possible to implement a larger number of PCI Express lines - M.2 devices have four such channels with a total bandwidth of 32 Gb / s. The interface also provides power to the plug-in expansion board, which, by the way, does not have to be a drive at all - M.2 allows you to connect Wi-Fi and Bluetooth controllers, GPS modules, NFC and other types of devices. It is also worth noting that, in addition to SATA 3.0 and PCI Express x4, the M.2 interface also provides USB 3.0, so it is not difficult to implement the devices listed above in the M.2 expansion card format.

The new Z97 chipset allows you to use physical contact lines in various configurations and, depending on the type of connected device, switch them to SATA, PCI Express or USB ports. The updated version of Intel Rapid Storage Technology is responsible for the operation of SSDs, including high-speed ones, guarantees the operation of standard and specialized functions, including as part of RAID arrays. In addition, the Z97 chipset provides compatibility with the next generation of processors (Haswell Refresh) without updating the motherboard BIOS.

Rice. 2. High-speed M.2 and SATA Express interfaces for storage subsystem. Wiring diagram for all slot and socket controllers to the Intel Z97 chipset.

Review of ASRock Z97 Extreme6 and Samsung XP941 | High performance motherboard storage

When the AHCI interface was introduced ten years ago, it was intended for mechanical drives and, in truth, perfectly replaced the previous connection method - IDE. And even when SSDs came along, this software interface to SATA was still pretty good. At least at the very beginning.

Now it limits the capabilities of SSD drives. They do not need to match mechanical drives in terms of form factor or the same type of software interface. In the material "An overview of five motherboards based on the Intel Z97 Express chipset, priced between $120 and $160" was shown an example of how the controller hub (Platform Controller Hub) offers the latest connectivity options for SSD-drives of different types and form factors. Thus, we are abandoning the disappearing SATA / AHCI in favor of PCIe and SATA Express, which even more clearly emphasize the difference between mechanical and solid state drives.

An increasing number of motherboards support new generation interfaces - M.2 PCIe- and SATA Express. None of these connectors will initially bring you a lot of benefits, but they will help pave the way for a new generation of storage for desktop PCs and mobile devices. For legacy hard drives, the SATA connector is intended, and new interfaces are already being used for new SSD drives. At some point in the future, we may be able to move away from AHCI as well, and instead take advantage of SSDs using the NVMe interface that will replace it.

Meet the ASRock Z97 Extreme6

We weren't overly impressed with the changes to the new platform, but we couldn't help but wonder: could this chipset bring out the best in storage? Meanwhile, there are not so many differences between the Z97 and Z87.

The board has ten SATA 6 Gb / s ports, six of which belong to the Intel Z97 Express PCH, and four more belong to a pair of ASMedia ASM1061 controllers. One connector is connected to the eSATA interface on the rear panel.

The SATA Express connector is combined with two SATA ports and an M.2 connector. As you can see, Intel's desire to implement new developments in the field of data storage based on core logic causes some limitations that we are used to talking about when talking about graphics (about sharing PCI-Express lanes and the like).

Surprisingly, although SATA Express is a completely new interface, its presence is not the biggest feature of the board. Rather, the Ultra M.2 x4 connector can be attributed to that. It is not connected to the PCH (like M.2 on ports 13 and 14 along with SATA Express), so it does not experience the same limitations, but instead uses four PCI Express 3.0 lanes, taking them from the processor and giving a bandwidth of 32 Gbps Although you won't be able to get performance above 4Gb/s, the right SSD drive can show very interesting results in testing.

Guess what we have prepared for our challenge? Samsung XP941, which is among the drives aimed at OEM builders. It uses four PCI Express lanes, and there is corresponding hardware for it. This will allow us to determine whether the Intel Z97 Express and ASRock Z97 Extreme6 by working together to make our dreams of data transfer speed come true.

Review of ASRock Z97 Extreme6 and Samsung XP941 | Discussing M.2 and SATA Express interfaces

M.2 PCIe

Intel makes the Z97 flexible and practical in a simple yet powerful way. This is achieved with ports 13 and 14 on the chipset, which are more flexible than they were in the past, when they supported two of the six SATA interfaces. Now more flexibility allows them to interact with two high-end connectivity interfaces - SATA Express and M.2 PCIe.

The M.2 PCIe interface is nothing new. We have previously published "SSD SanDisk A110 with PCIe interface: new M.2 connector", and not so long ago - "Plextor M6e 256GB PCI Express SSD Review: M.2 Desktop Form Factor" by testing an M.2 PCIe SSD on a small form factor card that is half the standard length and height. We were told that Plextor also planned to develop a version of the drive without an adapter, which meant that motherboards would be released with matching dual-lane connectors. So this day has come, although even with the start of sales of motherboards with two M.2 PCIe ports, SSD drives of this form factor are still few and rare for them.

In fact, it's easy to confuse M.2 for PCIe and SATA, and it's the same story as the mSATA confusion for mini-PCIe connectors. Until today, it has been increasingly difficult to distinguish between M.2 drives with SATA controllers and those compatible with PCIe. So let's just forget about SATA solutions and focus on drives that are designed for the PCI Express bus and have the M.2 form factor.

The flexibility of this form factor lies in the ability to install on a variety of single-sided and double-sided printed circuit boards. The 22mm wide M.2 device fits easily with the processor and NAND memory modules, and the longer circuit board will thus have more memory space. Considering that Samsung can place its drive Samsung 840 EVO mSATA With a capacity of 1 TB in about the same area as the M.2 2260 form factor (60 mm long), great prospects open up when working with the M.2 22110 (110 mm long). As the manufacturing process evolves and recording density increases, it's hard to imagine when M.2 will hit its capacity ceiling.

Most M.2 PCIe SSDs will use two PCI Express lanes (in the case of the Z97 Express, this means data transfer rates that are typical of second-generation devices). In its turn, Samsung XP941 unique in that it uses more than four lines, so it is the ideal drive for testing the motherboard ASRock Z97 Extreme6 and its four-lane PCI Express 30 Ultra M.2 connector.

SATA Express

SATA Express replaced SATA 6 Gb/s. The independent organization Serial ATA International Organization, which develops and standardizes SATA technology, realized the impracticality of an approach that was designed to double the speed of the SATA interface. Marvell's marketing director Paul Wassenberg told us last year at Flash Memory Summit 2013 that developing SATA Express is much more meaningful.

As the team testing the new connectivity method increased the number of PCIe lanes from one to eight, power consumption skyrocketed as more lanes were added. But with just two lanes, with 3rd generation bandwidth, the power consumption barely increased compared to the SATA 6Gb/s device, while the performance level was greatly improved. Given the challenges of the 12Gb/s SAS interface, it became clear that achieving cost-effectiveness in the case of SATA is very problematic, unlike SATA Express, given its relationship with PCI Express.

Unlike M.2 PCIe, which uses up to four lanes, SATA Express uses only two, but if the M.2 PCIe device is attached directly to the board, then SATA Express allows you to use remote connection using cables, as is the case with SATA. But there are also problems. An external PCIe SSD needs to receive a signal from the clock generator, and it will have to be transmitted using a shielded and more expensive cable. So you can do without costs here if the connection is provided by the solid-state drive itself.

Use one port, lose another

With the implementation of the SATA Express interface on the Z97, when using the new technology, you lose access to two SATA 6 Gb / s controllers and the M.2 interface, and vice versa, if you use M.2 (after all, there are many more of these devices), then use SATA Express no longer succeed.

For the sake of clarity, we have shown a diagram above that includes M.2 PCIe and SATA Express, along with the AHCI and NVMe protocols.

Thus, the M.2 and SATA Express interfaces in the Z97 are mutually exclusive and cannot be used simultaneously. Asus adds third-party SATA Express controllers to some boards, and apparently they are able to work independently of each other. And in the case of ASRock, four lines of the PCI Express controller are used for the Ultra M.2 connector. Let's study this system in more detail.

Review of ASRock Z97 Extreme6 and Samsung XP941 | Z97 Express: same bandwidth limits

It came as no surprise to us that the throughput of the Z97 platform controller hub when connected to the host processor is limited by the Intel DMI interface, which is based on PCI Express 2.0, and it will not be possible to provide the third generation speed due to the Skylake microarchitecture, which is two generations. But the Intel chipset doesn't need to take full advantage of PCIe 3.0 bandwidth, as it can really get more out of the eight PCIe lanes currently in use.

We know this because we've already seen the limitations of SSD arrays on Intel 6Gb/s ports. Last year we tested a range of SSD DC 3500 drives on a motherboard ASRock C226WS(English), and the limit was fairly obvious. The ASRock Z87 Express had six 6Gb/s ports, but three regular SSDs were enough to saturate the limited DMI bandwidth. The maximum speed was 1600 MB / s.

Well, in a four-lane Ultra-connector Samsung XP941 flies above the bar of 1000 MB / s. In principle, the fastest SATA 6Gb/s devices in a RAID 0 array can achieve the same result.

Arbitrary operation speed

Measuring the performance of arbitrary operations is another important metric. We already know that bandwidth limits are not a big problem when moving small blocks of data. Typically, a SATA 6Gb/s interface is sufficient for heavy serial workloads.

Speed ​​of arbitrary read operations in blocks of 4 KB

Given what we have seen above, it is easy to assume that Samsung XP941 capable of showing the highest performance when transferring a small number of blocks.

120,000 IOPS is an impressive result, but it doesn't reflect Samsung's hardware potential, unlike arbitrary operations. And the quad-lane Ultra M.2 slot delivers better results. The graph is not scaled enough to show how much performance is degraded when using a two-lane interface.

The results of using all three interfaces are approximately equal until the queue depth of 16 commands is reached. Desktop workloads don't tend to be as parallel, so Samsung XP941 does not have a clear advantage.

Speed ​​of arbitrary write operations in blocks of 4 KB

What happened was basically what we expected, based on the past performance of the SSD with PCIe interface and AHCI protocol. wins Samsung 840 Pro, although it is not the fastest drive in the world. Samsung XP941 with a dual-lane M.2 connector makes absolutely no impression. Things are a little better when connected to a four-lane interface, but not enough to choose it over SATA.

Conclusion: The random operation speed of a PCIe SSD is very pedestrian compared to the impressive performance in sequential operations, thanks in large part to AHCI. However, if you have not observed the work of another benchmark, you might think that Samsung XP941 is the best desktop SSD ever. However, our testing with Iometer does not necessarily reflect the performance of the device in real-world conditions. So we need a more detailed study.

Tom's Hardware Storage Bench v.1.0

Most Z97 Express motherboards will come with six SATA 6Gb/s ports, and some of them will get the dual-lane M.2 interface we're testing right now. Others will be equipped with SATA Express. The most significant difference in ASRock Z97 Extreme6 is an M.2 x4 slot associated with an Intel LGA 1150.

We have not yet tested SATA Express, because most of the first devices of this kind will be based on AHCI, which means they will not be too different from drives such as SanDisk A110 which we have already tested. Take a look at the results Samsung XP941 when connecting to a dual-lane M.2 interface and consider this interface as a replacement for SATA Express. With NVMe support, it will be even more interesting.

Our own benchmark, Storage Bench v1.0, uses two weeks of I/O information from a trace. Reproducing this pattern repeatedly to test drive performance results in results that are hard to interpret at first glance. The results practically do not take into account idle periods, that is, we can only take into account the time during which the drive was in an active state and executed commands from the host. Thus, having calculated the ratio of the drive's operating time to the amount of data processed during the trace, we get an indicator of the average data transfer rate (in MB / s), by which we can compare test participants.

This measurement system is not perfect. The initial trace logs TRIM commands during transit, but since the trace is organized on a drive without a file system, TRIM will not work even if it is sent during trace replay (which, unfortunately, is not the case). Still, tracing testing is a great way to capture times when a drive actually works, which has advantages over synthetic tests like Iometer.

Average data rate

Tracing in Storage Bench generates over 140 GB of writes during testing. Obviously, this puts SSDs below 180 GB at a deliberate disadvantage and favors those test participants whose capacity exceeds 256 GB.

In this abbreviated performance analysis, we do not show the results of many of the SATA 6 Gb/s drives that we encountered in our graphs. The results are generated in Windows 8.1, while our data library is based on Windows 7. However, we encountered some problems when working with the Ultra M.2 connector under an older operating system - if in Windows 7 PCIe drives were responsible for driver MSAHCI.SYS, then in Windows 8 - STORAHCI.SYS. We found a newer driver for less consistent latency and time to service resumption, which dramatically impacted performance. Meanwhile, Samsung 840 Pro is controlled by the Intel RST driver, so it doesn't matter to him. Then we explored the implications of both drivers in an SSD review. Plextor M6e 256GB PCI Express: M.2 desktop form factor.

The highest average data transfer rate achieved by the drive Samsung XP941 in the Ultra M.2 connector. He also takes second place - already in the M.2 connector. Behind him is Samsung 840 Pro with a SATA 6 Gb / s interface, which leaves behind the one connected to the PCI Express bus SanDisk A110, as well as the accumulator closing this table Plextor M6e .

However, in such a test, the most important metric is the time until service is resumed.

Time to resume service

Below is a graph of the times until read and write service is resumed (x- and y-axes, respectively). These values ​​are much more important than the average data rate. Using both metrics, we can get the most accurate device performance results with real workloads.

As usual, it is preferable to see these values ​​at the bottom left of the graph. Better performance can be seen in the place where the values ​​are located closer to the beginning.

You should not compare these results with others from our previous reviews. They were obtained under Windows 8.1, which is less adapted to PCIe SSDs due to the use of the STORAHCI driver. We expect things to change slightly with the introduction of NVMe, but right now Windows 8 allows us to run AHCI drives equally.

Bandwidth

Adobe Photoshop's heavy-duty tracing is the most intensive, which is why we use all of its 18 individual stages to determine latency and throughput.

Try to guess which of the lines on the graph corresponds to the performance Samsung XP941 .

If you haven't guessed yet, we'll tell you: this drive has the highest result on the chart, and with a big advantage. At each stage, its speed reaches 700 MB / s, and at the greatest depletion of the storage capacity, it drops to 500 MB / s - this is an incredible result. Even when plugged into a dual-lane M.2 slot, it's still very fast, it's just that there isn't enough support from the interface to deliver this level of performance.

Our first quad-lane M.2 SSD

The real storage revolution should come later, when the NVMe effect will be noticeable and there will be drives for connecting via SATA Express. Closer to the introduction of Intel Skylake, more attention will be paid to improving the performance of SSD drives with support for PCIe 3.0 controller hubs.

During testing ASRock Z97 Extreme6 we used several M.2 SSDs. ASRock has cleverly approached the issue of the location of the drive connectors that are located between the PCIe slots - in this case, the drives cannot physically conflict with GPUs and RAID cards. The Ultra M.2 connector can only be useful if manufacturers can create drives to connect to it. Of course, there is interest in drives with the highest speed, and the presence of such a connector on one board from one manufacturer can become something of a cult hit. Keep in mind that X99 is coming out soon and Haswell-E processors will have PCIe lanes. Will we see an Ultra M.2 connector again on an ASRock board?

I would like to believe. PCIe SSDs have been around for a few years and were the first to show how tacky it is to connect SATA devices to HBAs, and now we see that there are compact PCI Express connectivity solutions. The obscene cost of PCIe drives, which made them unavailable in enthusiast desktop systems, is a thing of the past. A performance Samsung XP941 match much more expensive enterprise-grade drives.

That's why you should consider M.2 PCIe SSDs if you're looking to upgrade. ASRock is to be commended for its innovation in ASRock Z97 Extreme6, where you can make a four-lane connection on a single board and use four lanes on the processor in order to provide fantastic bandwidth without any DMI restrictions. It is unfortunate that the ecosystem and the market are now so far from such an idea. It will be much easier to see this in early 2015, when everyone will appreciate NVMe (as an interface), as well as SATA Express and M.2 (as form factors). We hope that by then more motherboards will be able to unleash the full potential of super-fast SSDs.

Solid state drives of information, they are also SSD, are actively taking away the market share of personal computers from standard hard drives (HDD). In recent years, this trend has been especially noticeable due to the decrease in the cost of such storage devices. The price of SSD drives continues to be higher than that of HDD in terms of variations of the same volume, but the advantages of solid state storage justify it.

Pros and cons of SSD drives

Before purchasing an SSD drive, you need to evaluate the pros and cons that the user will receive from such a solution. The clear advantages of solid state drives over HDDs include the following:

The disadvantages of SSD drives include the high cost and complexity of acquiring such large-capacity drives.

How to choose an SSD drive

Solid state drives from various manufacturers are on the market. One company may have several lines of SSD drives, which vary in cost. When choosing an SSD, it is important to pay attention to the main parameters, choosing the options that are optimal for your tasks.

SSD volume

The main parameter when choosing a solid state drive is its volume. On the market you can find models with different free storage space, and before buying it is important to decide for what purpose the drive will be used.

Most often, SSD drives are purchased to increase the boot speed and operation of the operating system. If only Windows, Linux or another system will be installed on the disk, it makes sense to choose a drive with a capacity of 128 GB or 256 GB, depending on how much information the user stores in system folders, for example, "My Documents". On average, the operating system takes up 40-60 GB (if we are talking about Windows).

If you purchase a solid state drive as the only data storage in your computer, you should choose the size of the SSD, depending on the purpose of the PC and the activity on it.

SSD speed

The parameter that the disk manufacturer pays special attention to is the speed of work. On the box of each solid state drive, you can see information about how fast the storage device works for writing and reading. However, such figures are in most cases a marketing ploy, and in fact they are much lower. This is due to the fact that the disk manufacturer indicates the maximum sequential read / write speed, which does not play a big role in the process of standard work with a computer.

When choosing an SSD drive, you need to pay attention to its speed in random write and read operations of 4K blocks of information. It is with such data that the drive in the computer has to work for 90% of the time, occasionally reaching peak values. You can find out information about the real speed of an SSD using various programs, so before buying a drive, it is recommended that you familiarize yourself with tests of a specific disk model on the Internet.

Note: In most cases, the fastest drives in standard tasks are those that have a high maximum sequential read/write speed, but this is not always the case. In addition, the values ​​indicated by the SSD manufacturer may be overestimated.

SSD connection interface

SSD drives can be connected to a computer via one of the following interfaces:

• SATA 2;
• SATA 3;
• PCIe-E.

The fastest models use the SATA 3 interface, which has increased bandwidth.

As for PCIe-E SSD drives, they are almost impossible to find on sale. Such drives are used for specific tasks when it is not possible to connect an accessory via SATA of any version. Using a PCIe-E connector is inappropriate in terms of its bandwidth.

SSD memory chip

Depending on the memory chip used in the information storage, the number of bits in one cell, the speed of the drive, and the number of possible overwrites of information vary. In SSDs, you can find SLC, MLC, and TLC chips. Their comparative characteristics are given in the table:

On sale, you can most often find solid-state drives made on MLC chips. This is justified by the cost of their production and characteristics. Drives with SLC chips are more often used for servers, and SSDs based on them are expensive. As for TLC memory chips, they are common in removable media (flash drives) that do not require as many write / read cycles as SSD drives installed in a computer.

SSD controller

The speed, durability, support for additional technologies, and many other basic parameters largely depend on the stability and literacy of the controller in a solid state drive. You need to choose an SSD that has a drive from one of the leading companies in this field: Intel, Marvell, Sandforce or Indilinx.

Note: If a disk has a high speed of operation, but it has a bad controller from an unknown company, it is likely that such a drive will not work for a long time or it will have problems in the process of writing / reading information. That is why it is not recommended to buy "no-name SSD", about which there is no information, except for the maximum sequential read / write parameters.

Additional options and parameters of the SSD

When buying solid state drives, you will notice various items and options listed in their specifications. Let's break down the most common ones:

• IOPS- This indicator indicates how many operations per second the drive is capable of performing. You should pay attention to it, because in most cases it can tell more about the actual speed of the disk than information about the maximum read / write parameters;
• MTBF- the time of operation of a solid-state drive before failure. This parameter is measured in hours, and not all drive manufacturers indicate it. The MTBF is calculated based on the tests performed, during which the disks are loaded until they fail, after which the average values ​​are calculated;
• TRIM- an option that is present in the controller of almost all SSDs. It implies that the "brain" of the drive will always be aware of which cells have been cleared of the information previously contained in them, thereby the disk gets the opportunity to use them;
• S.M.A.R.T.- a diagnostic option that is present in almost every solid state drive of information. It is necessary so that the disk can independently evaluate its state, thereby roughly calculating the time before failure;
• Garbage Collection- an option designed to automatically clear memory from "phantom" files and other "garbage".

The myth that SSDs work many times less than HDDs has long been dispelled. With a standard boot, solid state hard drives can be used for 10 years or more without problems.