M.2

M.2
	A SanDisk 256GB PC SN7100s 256GB NVMe M.2 2230 SSD, 22 mm wide and 30 mm long with the key in the M position
Connects to	Motherboard via one of: PCIe 2.0 ×4; PCIe 3.0 ×4; PCIe 4.0 ×4; PCIe 5.0 ×4; Serial ATA 3.0; USB 3.0;
Common manufacturers	Intel; Phison; Realtek; Sandisk; Samsung; Silicon Motion; SK Hynix;
Design firm	PCI-SIG
Introduced	November 1, 2013
Dimensions	Width: 22 mm (0.87 in); Lengths: 30, 42, 60, 80 or 110 mm (1.2, 1.7, 2.4, 3.1 or 4.3 in);

A Kingston NV2 2TB NVMe Solid-state drive

A 2230 NVMe Gen4 Solid-state drive with its sticker removed to show the NAND and NAND controller (KIOXIA BG6)

Micron 2650 SSD 256GB Model MTFDKBK256TGW

M.2 (pronounced "em-dot-two"), formerly known as the Next Generation Form Factor (NGFF), is a specification for internally mounted computer expansion cards and connectors. It was developed to replace the older Mini SATA (mSATA) and Mini PCIe (mPCIe) standards.

M.2 supports a variety of module sizes and interface types, offering greater flexibility for modern devices. It is widely used in compact systems such as ultrabooks and tablet computers, particularly for solid-state drives (SSDs), due to its smaller size and higher performance compared to mSATA.

The M.2 connector can provide multiple interface options, including up to four lanes of PCI Express, as well as Serial ATA 3.0 and USB 3.0. The supported interfaces vary depending on the device and host implementation. M.2 modules and slots use different "keying" notches to indicate supported interfaces and to prevent incompatible installations.

For storage devices, M.2 supports both the older Advanced Host Controller Interface (AHCI) and the newer NVM Express (NVMe) protocols. AHCI provides compatibility with legacy SATA-based systems and operating systems, while NVMe is designed for high-speed SSDs and allows for much faster performance by supporting multiple simultaneous I/O operations.