M.2 M vs M.2 (B+M): Learn The Differences

Most computers come with at least one M.2 SSD drive. Two common M.2 types are the M.2 SATA and the M.2 NVME. Learn the difference between M.2 M vs M.2 (B+M).

What is an M.2 SSD, exactly?

An M.2 SSD is a tiny form factor solid-state drive (SSD) utilized in storage expansion cards placed inside. M.2 SSDs provide high-performance storage in tiny, power-constrained devices such as ultrabook laptops and tablet computers and adhere to a computer industry standard.

They’re often smaller than similar SSDs, such as the tiny Serial Advanced Technology Attachment (mSATA).

SSDs are solid-state flash memory storage devices that store permanent data. Unlike a hard disc drive (HDD), an SSD has no moving elements that might fail or cause it to spin up or down. 

The Next-Generation Form Factor was the initial name for the M.2 SSD interface standard. However, it was changed to M.2 after chevalier (pronounced M-dot-2). M.2 SSDs are ideal for gaming, 3D animation, video editing, and massive file transfers while constructing or updating a PC or laptop.

M.2 is compatible with various interfaces and applications, including PCIe and SATA. Solid-state drives aren’t the only M.2-compatible items. The M.2 standard also supports protocols like USB and Wi-Fi and may be utilized in graphics cards and artificial intelligence accelerator cards.

The SATA International Organization and the PCI Special Interest Group — a group of technology sector suppliers — collaborated to create the M.2 form-factor standard.

M.2 SSDs: Big Performance in Small Form Factor

Solid-state drives (SSDs) have gotten quicker and more capable of processing massive volumes of data in recent years. However, the interfaces to which they are attached restrict or hamper their full potential.

Serial ATA 3rd generation ports have a maximum native transfer rate of 6 Gb/s and were intended for significantly slower mechanical hard disc devices.

M.2 M vs M.2 (B+M)

The SATA 6 Gb/s connection limits the Mini-SATA (mSATA) interface, intended primarily to enable the smallest form factor for SSDs.

The M.2 standard, a specification for internally mounted computer add-in cards, was established to solve mSATA’s restrictions and give additional possibilities for small form factor cards, such as SSDs of different sizes and capacities. 

M.2 was legally renamed M.2 in 2013 after being known as the Next Generation Form Factor (NGFF). M.2 builds on the mSATA standard, which employs the physical card structure and ports of a PCI Express® Mini Card.

M.2, as the “successor” to mSATA, offers increased performance and capacity while reducing module footprint.

A SATA interface or a PCI Express (PCIe) lane is used to connect an M.2 SSD module to a host. Even though M.2 supports both SATA and PCIe, an M.2 module can only be plugged into one of the two interfaces.

Therefore check your motherboard documentation to ensure that your module fits and works with the appropriate socket.

What is the purpose of an M.2 SSD?

Wi-Fi, Bluetooth, near-field communication, and wireless wide area networks are just some device types that M.2 modules can interact with. However, M.2 form factors are most often linked with data storage SSDs.

A cable is not required to connect M.2 SSDs to a motherboard. Instead, they use a specialized M.2 connection slot to connect directly to the motherboard.

Both SATA and PCIe protocols may be utilized with an M.2 SSD. SATA is a connection and data transmission standard for hard disc drives and computer systems. PCIe, or serial extension bus, is a standard for connecting a computer to one or more peripheral devices.

M.2 SSDs also support PCIe-based non-volatile memory express (NVMe) drives. Over a PCIe bus, NVMe may speed up data transfer between client PCs and SSDs. NVMe support was created to help eliminate bottlenecks and boost performance. 

It also allows read and writing requests to be processed in parallel. NVMe compatibility may give up to five times more bandwidth than SATA M.2 models due to its architecture, allowing a computer to perform better for tasks like file transfers.

Single-sided and double-sided M.2 SSDs are available. Single-sided M.2 boards are utilized in ultra-thin laptops when space is constrained. On the other hand, double-sided chips take up more physical area but hold more data.

Module keys are notches on one end of the M.2 device that operates as connections. The rectangular M.2 modules. There is an edge connector on one side, and on the other, there is a mounting hole.

The edge connector has 75 pins and 75 locations. Each pin has a 50-volt and 0.5-amp rating.

Module keys M.2

The kind of M.2 product is identified by keys, which are notches in the edge connections of M.2 modules.

Module keys M.2

M.2 SSD modules are connected to circuit boards through connections on both sides. M.2 SSD cards, unlike mSATA, feature two kinds of connections or sockets: B key sockets and M key sockets. 

Both key kinds may be found on a single card. The key type determines the number of PCIe lanes supported by the socket. A B key can contain one or two PCIe lanes, whereas an M key can carry four. The M key edge connection has five pins, whereas the B key edge connector has six.

M.2 cards are keyed for A and E slots on a motherboard for Wi-Fi and Bluetooth wireless adapters. Most M.2 wireless cards support both A and E key slots.

Pros and Cons of M.2 SSDs

Using an M.2 SSD has many advantages:

Dimensions and capacity An M.2 SSD takes up significantly less space and consumes far less power in a laptop than a traditional SATA or Serial-Attached SCSI (SAS) interface solid-state drive. On the other hand, other form factors will likely be a better match if vast storage capacity is needed on a mobile device.

Performance. For example, M.2 SSDs based on NVMe standards may read and write data more quickly than SATA or SAS SSDs.

Adaptable user interface PCIe, SATA, USB 3.0, Bluetooth, and Wi-Fi are all supported by an M.2 SSD. If a customer buys a laptop with an M.2 interface, they will have a lot of peripheral gear configuration possibilities.

The following are some of the disadvantages of M.2 SSDs:

Price. An M.2 SSD is more expensive than a SATA SSD. Prices for 2.5-inch SATA SSDs have dropped as more of them are manufactured.

Capacity is limited. While 1 TB or 2 TB of storage is likely sufficient for most mobile apps, business storage systems need a larger capacity.

What are your M.2 SSD purchasing options?

Newer mobile computing devices often employ M.2 cards. M.2 SSDs are incompatible with older systems and may not fit big corporate storage devices since their form factor differs from mSATA cards. 

On the other hand, Enterprise storage providers are starting to use M.2 SSDs in their hybrid and all-flash arrays. M.2 SSDs’ tiny size and density allow storage suppliers to cram a lot of high-performance capacity into a small space, even with local capacities.

 Adata XPG SX8200 Pro

The Adata XPG SX8200 Pro or Samsung 970 EVO Plus are two instances of distinct M.2 SSDs to select from. The Adata M.2 SSD has a storage capacity of 256 GB to 2 TB with reading and sequential write speeds of 3,500 MB and 3,000 MB per second, respectively.

It has a 2 million-hour mean time between failures (MTBF). However, as compared to other options, random access rates fall short, which means that storage speeds will be slower.

M.2 suppliers

A 2 TB M.2 SSD normally costs between $150 and $200; lesser capacities are far less costly, with 256 GB M.2 SSDs costing under $50. As previously mentioned, Adata and Samsung, for example, provide a wide range of M.2 SSDs in various capacities. Other M.2 SSD manufacturers are:

Micron Technology owns Crucial, Kingston Technology, Plextor Team Group, and Toshiba.

Intel is also the leading manufacturer of M.2 wireless adapters.

What factors should you consider before purchasing an M.2 SSD?

As M.2 SATA drives and M.2 NVMe drives become less costly and more ubiquitous, they are usually recommended for new PC builds and upgrades.

When buying an M.2 device for a computer, the first thing to consider is whether it has one or two M.2 connectors. If a laptop meets M.2 standards, it will have a physical interface.

The operating system should already have the requisite Advanced Host Controller Interface drivers to allow M.2 storage card installation. 

The device’s fundamental input/output mechanism may need to be tweaked to detect the M.2 storage.

An M.2 SATA drive should be enough if the computer will be used mostly for everyday work or games. An M.2 NVMe drive should be used if the user demands the fastest compute performance or rapid sequential read and write speeds for use cases such as editing 4K video or massive file transfers.

If the motherboard lacks an M.2 slot, the user may purchase an M.2 drive on a card from companies like Asus or MSI. These mount the M.2 drive on a PCIe expansion card, allowing it to be used in PCIe slots.

What’s the difference between M.2, mSATA, and NVMe solid-state drives?

difference between M.2, mSATA, and NVMe solid-state

Although M.2 is sometimes described as an mSATA successor, mSATA SSDs are still available. They may continue to do so for some time, particularly on laptop systems that support that form factor.

M.2 and mSATA cards can’t be connected to the same devices since they’re different and have distinct connections, but they still have their uses.

M.2 refers to a kind of SSD that might be SATA or PCIe NVMe.

Most mSATA cards are slower and hold less data than M.2 SSDs. In contrast to mSATA, which only supports SATA interface standards, M.2 SSDs support a range of interface standards, including PCIe 3.0, SATA 3.0, and USB 3.0. M.2 SATA SSDs perform similarly to mSATA cards, whereas M.2 PCIe cards are faster.

Furthermore, SATA SSDs may reach 600 MB per second, whereas M.2 PCIe cards can reach 4 GB per second.

M.2 cards may also use the NVMe protocol thanks to PCIe support. Reduced latency, greater input/output operations per second, and lower power consumption provide NVMe devices a significant performance advantage over those with traditional interfaces.


As SSDs continue to transform the way businesses manage data, selecting the correct storage media in the proper form factor and the appropriate interfaces will be important.

M.2 SSDs, which provide smaller, quicker, and more efficient storage, broaden the options and solutions available for matching workloads to price and performance.

Over SATA and mSATA, the key advantage of an NVMe-based PCIe SSD is speed. NVMe drives clock in at 1 GB per second on the low end, whereas SATA drives clock in at 750 MB per second. M.2 NVMe SSDs are a suitable solution for applications that use a lot of hard drives or need a lot of hard drive reads and writes.