The M.2 form factor is a type of solid state drive card that inserts into a computer‘s motherboard. It serves as secondary, non-volatile memory data storage. An M.2 drive can attach to a motherboard through a designated port, rather than using a cable, which many traditional SSDs require.
M.2 drives use either a Serial AT attachment (SATA) or a PCI Express (PCIe) bus for data processing and storage; these are two different methods of connecting the drive to the computer. Computer specifications decide which is used, but some computers will allow both, and some will only allow one. It’s important to know which the computer supports before buying an M.2 drive, as some are only designed for SATA or PCIe. Using a PCIe connection is typically faster, though not exceedingly so.
PCIe versions 3.0 or later can also support Non-Volatile Memory Express (NVMe) technology. This significantly increases processing speeds for large data storage requirements. Though SSDs are a form of non-volatile data storage, NVMe uses a PCIe bus to bypass a system controller and process data as though it were in main memory. This is most useful for large applications or other data files that would otherwise take a long time to process. Not all older motherboards support NVMe technology, however, and cannot always be modified to do so. And not all PCIe ports will support NVMe, but using a PCIe connection for an M.2 drive is still faster than using SATA.
Some SSD users have noticed overheating issues, particularly with PCIe buses since they’re faster. Where the bus is located (and how much room it has within the computer) could affect its cooling and performance. Many SSDs are designed to automatically slow the drive’s work if it is overheating; they’re made with certain ideal temperature specifications. Drive performance will decrease if the drive exceeds its maximum heat recommendations.