Ssd disk in connector m 2 types. Important Features of Ultra-Fast M.2 Interface

M.2 connector (formerly known as Next Generation Form Factor and NGFF) is a specification included in the SATA 3.2 standard for computer devices and their connectors, approved by an international organization Serial ATA International Organization (SATA-IO) for tablets and thin computers. Created to replace the already outdated SATA, mSATA and Mini PCI-E formats. The key innovation of M.2 (NGFF) is support for data transmission over the line PCI Express 3.0 with a total theoretical throughput of up to 32 Gbps. Which is almost 6 times more than the SATA 3.0 standard allowed.

M.2 expansion cards can provide various functions eg: Wi-Fi, Bluetooth, satellite navigation, NFC radio communications, digital radio, Wireless Gigabit Alliance (WiGig), Wireless WAN (WWAN) and others. Fast and compact solid-state flash drives (SSDs) are often manufactured in the form of M.2 modules.

The use of a new device format made it possible to use the DevSleep minimum power consumption mode, the Transitional Energy Reporting power management mechanism, the Hybrid Information mechanism (increasing the efficiency of data caching in hybrid drives) and Rebuild Assist (a function that speeds up the process of data recovery in RAID arrays).

Form factor and keys.

To put it simply, M.2 is a mobile version of the protocol SATA Express, described in the SATA 3.2 specification for tablets and thin computers. This interface can be compatible with devices using SATA, PCI Express, USB 3.0, I2C and others protocols. M.2 supports up to four PCI Express 3.0 lanes, while SATA Express connectors transfer data over only two PCI Express 2.0 lanes. The boards have 4 widths (12, 16, 22 and 30 mm) and 8 lengths (16, 26, 30, 38, 42, 60, 80 and 110 mm).

In addition to the length and width of devices connected to M.2, standards for the thickness of components on the board are described. Also, single-sided and double-sided mounting options (Single Sided and Double Sided), divided into 8 more types. For a more convenient understanding, I will provide a table below:

The thickness of the components on the board of the device connected to M.2 (dimensions are indicated in millimeters).

To indicate the M.2 type, devices are marked with a code according to the scheme WWLL-HH-K-K or WWLL-HH-K, where WW and LL are the dimensions of the module in width and length in millimeters. HH encodes whether the module is single-sided or double-sided, as well as the maximum allowable height (thickness) of the components placed on it, for example “D2”. Part K-K denotes key cuts; if the module uses only one key, one letter K is used. If K-K is used, then the module has 2 keys.

Diagram with detailed transcript all markings indicating the quantities.

As of 2018, the most popular sizes are defined as: width 22 mm, length 80 or 60 mm (M.2-2280 and M.2-2260), less often 42 mm. Many early M.2 drives and motherboards used the SATA interface, the most popular dongles for them are B(SATA and PCIe x2). Modern motherboards implement the M.2 PCI Express 3.0 x4 slot and the corresponding key M(SATA and PCIe x4). Devices designed for use in M-keyed sockets are not electrically compatible with B-keyed sockets, and vice versa, unless otherwise stated. Although it is not uncommon, as practice shows, they are physically compatible (if turned over). To connect expansion cards, such as WiFi, modules of size 1630 and 2230 and dongles are used A or E.

M.2 - the board must not only fit in size, but also have a key arrangement compatible with the slot. The keys limit mechanical compatibility between different connectors and M.2 form factor cards and prevent incorrect installation drives in the slot.

Actually, before purchasing an expansion card, you need to check with the manufacturer about the type of connector and compatible dimensions (length, width, thickness, single-sided and double-sided).

What are Socket 1, Socket 2, Socket 3 as applied to M.2 (NGFF) devices?

Indeed, the concept of a socket also appears for M.2 devices. I’m thinking of creating groups of M.2 connectors on Socket 1,2,3 for a simplified separation of devices that are not compatible with each other. Formally dividing all types of devices into 3 easy-to-understand types.

The division principle is clearly shown in the following table:

Let's look at an example based on real online stores:

SSD drive SAMSUNG M.2 860 EVO 250 GB M.2 2280 SATA III (MZ-N6E250BW)

From the description it is clear that in front of us Samsung SSD with a capacity of 250Gb, designed for use in the M.2 connector. Next comes the marking “2280” indicating the physical size - 22 mm wide, 80 mm long. Not a word about thickness and single-sided or double-sided design. IN in this case You will have to check from other sources or the drive manufacturer. After indicating the size marking it is written - SATA III. What does this mean? This means that the drive uses the SATA III logical interface. That is, we still have the same classic SATA drive, but made to fit the dimensions and M.2 connector. The speed advantages of PCI Express are not used here.

That's all, the seller's description is exhausted. What are we still missing? We lack an explicit indication of the type of connector key; let this remain on the conscience of the seller. But we visually see 2 slots, this means that this drive can be used as part of motherboards with a connector like B and type M. This is a visual assessment, I repeat again - you need to check with the manufacturer.

Let's try again:

SSD Samsung drive 960 EVO M.2 250 GB M.2 PCI-E TLC MZ-V6E250BW

Here we see the Samsung 960 EVO SSD, also on the M.2 connector. No labeling at all physical dimensions and type, presumably also “2280” (always need to be clarified from other sources). The following are PCI-E and TLC, what does this mean? This means that the device uses the PCI Express logical interface (which 2.0 or 3.0 is not clear, and how many 2x-4x lanes are also not known). TLC is a type of memory chip device. At this point, the online store considered the description sufficient. I think the warranty will tell him otherwise later...

But visually we see in this image one slot in the M.2 connector (presumably corresponding to the key M). And here you need to be careful, the device may physically fit into the connector B. And most likely, it will burn the board and the device. Therefore, it is necessary to know exactly what type of connector is installed on the board and which one is purchased.

Implementation of logical interface and command set.

For M.2 expansion cards, there are three options for implementing the logical interface and command set, similar to the SATA Express standard:

“Legacy SATA” Used for SSDs with a SATA interface, AHCI driver and speeds up to 6.0 Gbps (SATA 3.0) “SATA Express” using AHCI Used for SSDs with a PCI Express interface and an AHCI driver (for compatibility with big amount operating systems). Due to use AHCI performance may be slightly below optimal (obtained with NVMe) since AHCI was designed to interoperate with slower drives with slower sequential access(for example, HDD), and not for SSDs with fast random access. "SATA Express" using NVMe Used for SSDs with a PCI Express interface and a high-performance NVMe driver designed to work with fast flash drives. NVMe was designed to take advantage of the low latency and parallelism of PCI Express SSDs. NVMe makes better use of parallelism in the host computer and software, requires fewer data transfer stages, provides a deeper command queue, and more efficient efficient processing interrupts.

What is NVMe?

NVM Express ( NVMe, NVMHCI - from English. Non-Volatile Memory Host Controller Interface Specification). Logical interface NVM Express was designed from the ground up with the main goals being low latency and efficient use high parallelism of solid-state drives due to the use of a new set of commands and a queue processing mechanism optimized for work with modern multi-core processors.

The NVMe protocol speeds up I/O operations by eliminating the SAS (SCSI) command stack. NVMe SSDs connect directly to the PCIe bus. Applications receive dramatic performance gains from shifting I/O activity from SAS/SATA SSDs and HDDs to NVMe SSDs. Memory devices of the new type of storage are non-volatile and the latency when accessing them is significantly lower - at the level of latencies of RAM (volatile) memory.

NVMe Controller Shows It All benefits of SSD: very low access latencies and huge queue depth for read and write operations. The extremely low latency of storage devices significantly reduces the likelihood of data table locks during updates. This is critical for multi-user databases with complex and interconnected tables.

Very important: in UEFI Motherboard BIOS The board must contain an NVMe driver to load the OS from the corresponding drive.

Conclusion.

In conclusion, the advantages become obvious accepted by the standard SATA 3.2. The emergence of new specifications and connectors will expand the choice of compatible expansion cards for both laptops and desktop computers. Will also increase overall performance computing systems from laptop to server.

The interface itself is fraught with a large number of traps for both the average user and the professional. Perhaps this is due to its novelty, or maybe some “dampness”.

In any case, I tried to collect as much as possible important information. Any questions you may have can be asked in the comments to the article. If the article helped you, you can thank me by sending donations to a Yandex wallet, the form for sending money is located at the very bottom of the site (footer). Thank you for your attention to my article.

Read about the advantages and disadvantages of the M.2 form factor, which drives support the M.2 slot, what connectors M.2 drives use, what is needed to install an M.2 card, etc. M.2 is new open format for productive computer systems, but is everything so clear? Manufacturers of solid-state SSD drives such as Samsung, Intel, Plextor, Corsair use this format to save space and energy costs. This is very important factors in the production of modern ultrabooks and tablets. However, purchasing an M.2 drive to upgrade your device requires some forethought.

M.2 is not just an evolutionary form factor. Potentially, it should completely replace the entire Serial ATA format. M.2 can interface with SATA 3.0 (all drives on modern desktop PCs are connected with such cables), PCI Express 3.0 (this interface is used by default for video cards and other devices) and even USB 3.0.

Potentially any SSD or HDD drive, memory card or flash drive, GPU or any USB a gadget with low power consumption, can be installed on a card with an M.2 connector. But it's not that simple. For example, there are only four PCI Express lanes in one M.2 slot, which is a quarter of the number that graphics cards need, but the flexibility in this tiny little slot is impressive.

When using the PCI bus instead of the SATA devices M.2 can transfer data faster than 6 times. Final speed depends on the capabilities of the motherboard and the M.2 card itself. An M.2 SSD drive will work much faster than a similar one SATA drive if your motherboard supports PCI 3.

What drives support the M.2 slot?

On this moment M.2 is used as an interface for ultra fast SSD disks on both laptops and workstations. If you go to a computer store and ask for an M.2 drive, they will almost certainly show you an SSD with an M.2 connector. But only if you can find a retail computer store that is still in business today.

Some laptop models also use the M.2 port as a means wireless connection, installing tiny, low-power cards that combine Wi-Fi and Bluetooth radios. This is less common on desktop computers, where it is more convenient to use USB or PCIe 1x connectors (though there is no reason why you couldn't do this on a compatible motherboard).

Manufacturers computer hardware They are in no hurry to use this slot for other devices. No one has yet presented a video card on the M.2 connector, but Intel is already selling its over fast memory Optane customers.

Does my computer support an M.2 slot?

If your computer was manufactured and built in the last few years, then it almost certainly has an M.2 slot. Unfortunately, the flexibility of the format does not mean that the slot itself is as easy to use as any other USB device. As a rule, cards with an M.2 slot are quite long. Before purchasing an M.2 SSD drive, check the board dimensions according to the specifications and make sure that your computer or laptop has room to install them. In addition, M.2 devices have different connectors. Let's look at these 2 factors in more detail.

What is the length of the M.2 card?

For desktop PCs, length is usually not an issue. Even a tiny Mini-ITX motherboard can easily accommodate an M.2 board, the length of which ranges from 30 to 110 millimeters. Typically, motherboards have a hole for a small screw that holds the board securely in place. The length of the supported M.2 chip is indicated next to the mount.

All M.2 drives use a fixed width of 22 millimeters, so the size difference is only expressed in length. Currently the following options are available:

• M.2 2230: 30mm;
• M.2 2242: 42 mm;
• M.2 2260: 60 mm;
• M.2 2280: 80 mm;
• M.2 2210: 110 mm.

Some motherboards offer the ability to attach a screw at any of these intervals.

What connectors do M.2 drives use?

Although the M.2 standard uses the same 22mm wide slot for all cards, it is not the same for all devices. Since M.2 is designed to be used with many various devices, it has some connection differences:

• B Key: The gap on the right side of the card (to the left of the host controller) is used, with six pins to the right of the gap. This configuration supports PCIe x2 buses.
• M Key: uses the gap on the left side of the map ( Right side main controller), with five pins to the left of the gap. This configuration supports PCIe x4 bus connections for double the data throughput.
• B+M Key: uses both of the above gaps, with five pins on the left side of the card and six on the right. Such cards are limited to PCIe x2 speed.

What is needed to install an M.2 card?

Most M.2 cards are SSD drives and are automatically recognized by your operating system based on AHCI drivers. For Windows 10, most Wi-Fi and Bluetooth cards are also automatically recognized and installed standard drivers. However, you may need to enable the M.2 slot through a setting in your computer's BIOS or UEFI. You will also need a screwdriver to secure the device with a screw to the motherboard.

Is it possible to add an M.2 card to a PC if it does not have a slot?

This is not possible for laptops because modern devices have a very compact design and do not allow any unplanned device inside the case. You're in luck if you're using a desktop PC. There are adapters on the market that use the PCIe x4 slot on your motherboard.

Remember, if your motherboard can't boot from PCIe, then you won't be able to use the M.2 drive as a boot drive, which means you won't benefit from high speed. If you want to take full advantage of an M.2 drive, it's best to use a motherboard that supports the new standard.

If desktop hard disks have existed in the 3.5-inch form factor for many years, SSDs have been produced in the 2.5-inch format from the very beginning. It was great for small SSD components. However, laptops have become thinner and thinner, and 2.5-inch SSDs no longer meet the small size criterion. 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 low speed of SATA. mSATA drives are physically identical to Mini PCI Express modules, but electrically mSATA and mini PCIe are incompatible. If the socket is designed to accommodate mSATA drives, you will only be able to use those. On the contrary, if the socket is designed for mini PCI Express modules, the drives mSATA SSD You can insert them, but they will not work.

The mSATA standard can be considered obsolete today. It gave way to the M.2 standard, which was originally called Next Generation Form Factor (NGFF). The M.2 standard provides manufacturers with greater flexibility in SSD dimensions, since the drives are much more compact, allowing eight length options, from 16 to 110 mm. Also M.2 supports different variants interfaces. Today, the PCI Express interface is increasingly used, which will dominate in the future, since it is much faster. But the first M.2 drives relied on the SATA interface, and USB 3.0 was theoretically possible. However, not all M.2 slots support all mentioned interfaces. Therefore, before purchasing 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 a cable is no longer required; the drive is inserted directly into the motherboard slot. However, connecting via cable is also possible. But for this, the motherboard must have a corresponding 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 6 Gb/s, so it is backward 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, since SATA Express drives are electrically connected to the PCI Express bus. That is, SATA Express drives on “pure” SATA 6 Gb/s ports do not work. But SATA Express relies on only two PCIe lanes, meaning the bandwidth will be half that of M.2.

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

Of course, most desktop computers have regular PCI Express slots, so it's possible to install an SSD directly into a slot like 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 SSD with PCI Express interface demonstrated throughput more than two gigabytes per second - but only when suitable connection. Modern M.2 SSDs are usually designed for four third-generation PCI Express lanes; only this interface allows them to unlock their performance potential. With the old PCIe 2.0 standard and/or fewer lines SSD drives will work, but you will lose a very significant part of the performance. If in doubt, we recommend checking your motherboard's user manual for the M.2 lane configuration.

If the motherboard does not have an M.2 slot, you can install such a drive via an expansion card, for example, in a slot for a second video card. However, in this case, most often the video card will no longer be supplied with 16, but 8 PCI Express lines. However, this will not affect the performance of the video card so seriously. The following table summarizes information about modern interfaces:

Don't know which interface to buy an SSD drive with? Then this article will help you with your choice! Today we will look at what interfaces exist for SSDs.

SSD drives have already been installed in almost all modern gaming PCs and laptops. Not surprising - the storage capacity is increasing, the price is decreasing, and the choice is huge. Yes, not all of them are as good as we would like, but today we will not talk about that. But besides choosing a manufacturer and model, another question arises: what interface do we need a drive with?

Now manufacturers continue to develop in two directions - the transition from SATA to PCI-Express and the use of other physical interface. In the second case, several new types of connectors appeared before us. All this can take the user by surprise in case of upgrading his system.

SATA
We are already accustomed to the fact that SSD drives with a SATA interface are 2.5″ devices with a capacity of up to 1 TB. SATA III (6 Gb/s) interface provides real speed data transfer up to 550 MB/s. Such drives are most often found in PCs, monoblocks and laptops, while possessing maximum compatibility with platforms. But ultrabooks (for example, ASUS Zenbook) physically cannot accommodate such drives.

PCI-Express
Due to the peculiarity of the physical interface, PCI-Express SSD drives are used exclusively in PCs and servers. Depending on the drive, used PCI-Express interface x2, x4 or x8. Advantage PCI-Express drives is the speed, because it significantly exceeds that available with SATA III (550 MB/s) - here we will already get more than 780 MB/s ( given speed taken from ROG RAIDR Express). And in more expensive solutions - more than a gigabyte per second.

mSATA
The mSATA (mini-SATA) interface can be found on some desktop motherboards (for example, the ASUS Maximus V line) and in a considerable number of laptops. Drives with this interface comply with the SATA III specification (6 Gb/s) and can reach data transfer rates of 550 MB/s. The mSATA interface and devices are externally indistinguishable from the mini-PCI-Express interface and devices, but they are completely incompatible and installing an mSATA device in a mini-PCI-Express slot can lead to failure of these components. Currently, mSATA is already leaving the market, as it was replaced by more new interface— M.2.

SATA Express
The SATA Express interface is designed specifically for PCs and has a theoretical throughput of 10 Gbps (40% faster than SATA III). The new interface involves the use of a completely different connector on the board and on the drive, as well as the use of a new cable for transmitting information. For example, the new interface is already available on the motherboard ASUS board Z87 Deluxe/SATA Express, and will also be available on new motherboards based on Intel chipset Z97. True, the drives themselves will appear only by summer. You can connect one SATA Express drive or two SATA III drives to one connector.

M.2 Connector (NGFF)
Previously known as NGFF (Next Generation Form Factor - after mSATA), M.2 drives have taken a place in laptops and ultrabooks. But some desktop motherboards will also have this connector. The M.2 interface can support both PCI-Express lines and SATA lines. But in most cases, PCI-Express lines are used. So when choosing an M.2 drive, you should first find out from the specification of your device what type of M.2 interface you have on the board.

Whether in the past or this year, articles about SSDs can safely begin with the same passage: “The solid-state drive market is on the verge of serious changes.” For several months now, we have been looking forward to the moment when manufacturers finally begin releasing fundamentally new models of mass-produced SSDs for personal computers, which instead of the usual SATA interface 6 Gb/s will use the faster PCI Express bus. But the bright moment, when the market is flooded with fresh and noticeably more high-performance solutions, everything is postponed and postponed, mainly due to delays in bringing the necessary controllers to fruition. Those single models of consumer SSDs with the PCI Express bus, which do become available, are still clearly experimental in nature and cannot amaze us with their performance.

Being in such anxious anticipation of change, it is easy to lose sight of other events that, although they do not have a fundamental impact on the entire industry, are nevertheless also important and interesting. Something similar happened to us: new trends, to which we had paid almost no attention until now, have spread unnoticed in the consumer SSD market. SSDs of a new format - M.2 - have begun to appear on sale en masse. Just a couple of years ago, this form factor was talked about only as a promising standard, but over the past year and a half it has managed to gain a huge number of supporters both among platform developers and among SSD manufacturers. As a result, today M.2 drives are not a rarity, but an everyday reality. They are produced by many manufacturers, they are freely sold in stores and are installed in computers everywhere. Moreover, the M.2 format has managed to carve out a place for itself not only in mobile systems for which it was originally intended. Many motherboards for desktop computers today are also equipped with an M.2 slot, as a result of which such SSDs are actively penetrating classic desktops as well.

Considering all this, we came to the conclusion that it is necessary to pay close attention to solid-state drives in the M.2 format. Despite the fact that many models of such flash drives are analogues of the usual 2.5-inch SATA SSDs, which are tested in our laboratory on a regular basis, among them there are also original products that do not have twins of the classic form factor. Therefore, we decided to catch up and hold a unified summary testing The most popular capacities of M.2 SSD available in domestic stores are 128 and 256 GB. The Moscow company “ Regard", offering an extremely wide range of SSDs, including those in the M.2 form factor.

⇡ Unity and diversity of the world M.2

M.2 slots and cards (formerly this format called Next Generation Form Factor - NGFF) were originally developed as a faster and more compact replacement for mSATA - a popular standard used by solid-state drives in various mobile platforms. But unlike its predecessor, M.2 offers fundamentally greater flexibility in both logical and mechanical parts. The new standard describes several options for the length and width of cards, and also allows the use of both SATA and the faster PCI Express interface to connect solid-state drives.

There is no doubt that PCI Express will replace the drive interfaces we are used to. Direct use of this bus without additional add-ons allows you to reduce latencies when accessing data, and thanks to its scalability, it significantly increases throughput. Even two PCI Express 2.0 lanes can provide noticeably higher data transfer speeds compared to familiar interface SATA 6 Gb/s, and the M.2 standard allows you to connect to an SSD using up to four PCI Express 3.0 lanes. This foundation for increased throughput will lead to the emergence of a new generation of high-speed SSDs capable of delivering more fast loading operating system and applications, as well as reducing delays when moving large amounts of data.

Formally, the M.2 standard is a mobile version of the SATA Express protocol, described in the SATA 3.2 specification. However, it turned out that last couple Over the years, M.2 has spread much more widely than SATA Express: M.2 connectors can now be found on current motherboards and laptops, and SSDs in the M.2 form factor are widely available for sale. SATA Express cannot boast of such support from the industry. This is partly due to the greater flexibility of M.2: depending on the implementation this interface can be compatible with devices using SATA, PCI Express and even USB 3.0 protocols. Moreover, in its maximum version, M.2 supports up to four PCI Express lines, while SATA Express connectors are capable of transmitting data over only two such lines. In other words, today M.2 slots seem to be not only convenient, but also a more promising foundation for future SSDs. Not only are they suitable for both mobile and desktop applications, but they are also capable of delivering the highest throughput of any consumer SSD connectivity option available.

However, given the fact that the key property of the M.2 standard is the variety of its types, it should be borne in mind that not all M.2 drives are the same, and their compatibility with various options the corresponding slots are a different story. To begin with, the M.2 form factor SSD boards available on the market are 22mm wide, but come in five lengths: 30, 42, 60, 80, or 110mm. This dimension is reflected in the markings, for example, the M.2 2280 form factor means that the drive card is 22 mm wide and 80 mm long. For M.2 slots, a complete list of dimensions of storage cards with which they can be physically compatible is usually indicated.

The second feature that differentiates different M.2 variants is the “keys” in the slot slot and, accordingly, in the blade connector of the cards, which prevent the installation of drive cards in connectors that are logically incompatible with them. At the moment, M.2 SSD uses two key layout options out of eleven described in the specification different provisions. Two more options have found application on WLAN and Bluetooth cards in the M.2 form factor (yes, this also happens - for example, wireless adapter Intel 7260NGW), and seven key positions are reserved for the future.

M.2 slots can only have one key cutout, but M.2 cards can have multiple key cutouts at once, making them compatible with multiple types of slots at the same time. The type B key, located instead of pins numbered 12-19, means that no more than two PCI Express lanes are connected to the slot. The M type key, occupying pin positions 59-66, means that the slot has four PCI Express lanes and therefore can provide more high performance. In other words, the M.2 card must not only be the right size, but also have a key layout compatible with the slot. At the same time, the keys not only limit mechanical compatibility between various connectors and boards of the M.2 form factor, but also perform another function: their location prevents drives from being installed incorrectly in the slot.

The information given in the table should help to correctly identify the type of slot available in the system. But you need to keep in mind that the possibility of mechanical mating of the slot and connector is only necessary, but not sufficient condition for their full logical compatibility. The fact is that slots with keys B and M can accommodate not only the PCI Express interface, but also SATA, but the location of the keys does not provide any information about its absence or presence. The same applies to M.2 card connectors.

There is another problem. It lies in the fact that many motherboard developers ignore the requirements of the specifications and install the “coolest” slots with an M type key on their products, but only install two of the four assigned PCIe lanes on them. In addition, the M.2 slots available on motherboards may not be compatible with SATA drives at all. In particular, it is guilty of its love for installing M.2 slots with reduced SATA functionality. ASUS company. These challenges are adequately responded to and SSD manufacturers, many of whom prefer to make both key cutouts on their cards at once, which makes it possible to physically install drives in M.2 slots of any type.

As a result, it turns out that to determine real opportunities, compatibility and the presence of a SATA interface in M.2 slots and connectors is impossible based on external signs alone. That's why full information information about the implementation features of certain slots and drives can only be obtained from the passport characteristics of a particular device.

Fortunately, at the moment the range of M.2 drives is not so large, so the situation has not yet become completely confusing. In fact, there is currently only one model of M.2 drive with a PCIe x2 interface on the market - Plextor M6e - and one model with a PCIe x4 interface - Samsung XP941. All other flash drives available in stores in the M.2 form factor use the familiar SATA 6 GB/s protocol. Moreover, all M.2 SSDs found in domestic stores have two key cutouts - in positions B and M. The only exception is the Samsung XP941, which has only one key - in position M, but it is not sold in Russia.

However, if your computer or motherboard has an M.2 slot and you plan to fill it solid state drive, then you need to check a few things first:

• Does your system support M.2 SATA SSD, M.2 PCIe SSD, or both?
• If the system has support for M.2 PCIe drives, how many PCI Express lanes are connected to the M.2 slot?
• What arrangement of keys on the SSD card is allowed by the M.2 slot in the system?
• What is maximum length M.2 card that can be installed in your motherboard?

And only after you can definitely answer all these questions, you can proceed to choosing the appropriate SSD model.