The M.2 Standard: Past, Present, and Future

It has been 13 years since the M.2 (pronounced “M dot two”) standard was introduced in 2012. Formerly known as Next Generation Form Factor (NGFF), this specification for internally mounted computer add-in cards gained widespread adoption for high performance, compact size, interface versatility, and application flexibility. M.2 brings higher performance and capacity while minimizing module footprint for laptops, desktops, servers, and industrial systems.

Turbo-Boosting the Speed Shift: SATA to PCIe NVMe

Created to overcome SATA 6 Gb/s limitations and support solid state drives (SSDs) in diverse sizes/capacities, M.2 accommodates both SATA and PCIe for flexible performance and cost options. PCIe M.2 SSDs, leveraging up to x4 PCIe lanes and NVMe, now far outpace SATA SSDs for speed, responsiveness, latency, and efficiency.

The table below presents an overview of speed evolution from SATA to the latest PCIe standards and their use cases.

Sizes, Keys/Connectors, and Sockets: What the Nomenclature Means

M.2 modules are used for SSDs and wireless adapters (Wi-Fi®, Bluetooth®, NFC, WWAN, etc.). The PCIe M.2 specification employs a standard naming convention for clear compatibility between modules and motherboard sockets.

M.2 Naming Example

2280-D2-M Width: 22 mm Height: 80 mm D2 Label: Double-sided, max. height 1.35 mm/top and bottom Key ID: M (PCIe x4)

Sockets

The specification defines three “sockets” with unique mechanical keys; modules are not interchangeable between socket types.

• Socket 1: Wi-Fi®, Bluetooth®, NFC, Wi-Gig modules
• Socket 2: WWAN, SSD/SSD Cache (may fit B+M-keyed SSDs—check docs)
• Socket 3: SSD Drive, SATA or up to four PCIe lanes

Keys/Connectors

Edge connectors—“keys”—prevent incompatible insertion. M.2 SSDs use three main key types:

B Key: For moderate bandwidth, rugged or legacy devices.
M Key: For high-performance SSDs and servers.
B+M Key: Broad compatibility, but limited to PCIe x2/SATA speeds.

ATP’s M.2 Modules

ATP’s M.2 modules are available in the following form factors:

Type	Model / Interface	Notes
Connectorized	M.2 2280, PCIe Gen4 x4, M Key	High-speed, high density for server/datacenter/enterprise
Connectorized	M.2 2242/2230/other, PCIe Gen3 x4, M Key	Rugged/industrial/legacy/custom footprints
Connectorized	M.2 2280, 2242, SATA, B+M Keyed	Legacy SATA compatibility, field and fleet upgrades
Soldered Down	PCIe M.2 Type 1620 HSBGA	Embedded, ultra-rugged form factors

Labels: Single- or Double-Sided?

Nomenclature labels S1–S5 and D1–D8 indicate maximum component thickness and whether the module is single- or double-sided. Single-sided = components only on top; double-sided = chips on both top and bottom, for maximum capacity. Always check clearance in the host device.

Keeping it Cool: Intelligent Thermal Management

PCIe Gen4/Gen5 SSDs reach blazing speeds and generate significant heat. ATP integrates both hardware (heatsinks, copper/aluminum fin or groove designs) and firmware (Host Controlled Thermal Management) to maintain performance and SSD longevity. Modular heatsink solutions are tailored to fit single- or double-sided SSDs in all host devices.

1. Fit: Heatsink height/thickness must match SSD/module/host clearance.
2. Material: Select copper/aluminum, fin/grooved, clip-on/screw-down for best cooling and install safety.
3. System airflow: Effective cooling depends on your host’s fans, vents, and usage pattern.

ATP Heat Dissipation Solutions (Thermal Joint Validation Service)

ATP's heat dissipation solutions include continuous evaluation of mechanical/firmware designs. The ATP Thermal Joint Validation Service ensures optimal thermal management for every application.

Conclusion