It is up to the manufacturer of the M. 2 host or device to select which interfaces are to be supported, pci express m.2 nvme specification pdf on the desired level of host support and device type. 2 connector has different keying notches that denote various purposes and capabilities of M. 2 hosts and modules, preventing plugging of M.
2 modules into feature-incompatible host connectors. 2 as a new format for storage devices and specifies its hardware layout. PCI Express and SATA storage devices may exist in the form of M. 2 specification, in its revision 1. There are three options available for the logical device interfaces and command sets used for interfacing with M. 2 storage devices, which may be used depending on the type of M.
Used for SATA SSDs, and interfaced through the AHCI driver and legacy SATA 3. SATA support in operating systems at the cost of not delivering optimal performance by using AHCI for accessing PCI Express SSDs. PCI Express lanes, as a high-performance and scalable host controller interface designed and optimized especially for interfacing with PCI Express SSDs. PCI Express SSDs, and complementing the parallelism of contemporary CPUs, platforms and applications. The socket is keyed in the M position and provides two positions for the mounting screw, accepting 2260 and 2280 sizes of M.
2 has been designed from the ground up to maximize usage of the PCB space while minimizing the module footprint. As the result of the M. 2 standard allowing longer modules and double-sided component population, M. 75 positions with up to 67 pins, 0.
2 standard allows module widths of 12, 16, 22 and 30 mm, and lengths of 16, 26, 30, 38, 42, 60, 80 and 110 mm. Initial line-up of the commercially available M. 2 expansion cards is 22 mm wide, with varying lengths of 30, 42, 60, 80 and 110 mm. 2 module is installed into a mating connector provided by the host’s circuit board, and a single mounting screw secures the module into place. Usually suitable screws are provided with the hardware component on which the M. 2 to PCI-E adapter, etc. The screw specifications for thread, length, and head-type can vary depending on the hardware manufacturer.