Understanding SSD Technology: NVMe, SATA, M.2
NVMe (Non-Volatile Memory Express) is a communications interface and driver that defines a command set and feature set for PCIe-based SSDs with the goals of increased and efficient performance and interoperability on a broad range of enterprise and client systems.
NVMe was designed for SSD. It communicates between the storage interface and the System CPU using high-speed PCIe sockets, independent of storage form factor. Input/Output tasks performed using NVMe drivers begin faster, transfer more data, and finish faster than older storage models using older drivers, such as AHCI (Advanced Host Controller Interface) a feature of SATA SSDs. Because it was designed specifically for SSDs, NVMe is becoming the new industry standard for both servers in the data centre and in client devices like laptop, desktop PCs and even next gen gaming consoles.
NVMe technology is available in a number of form factors such as the PCIe card slot, M.2, and U.2. While there are SSDs that use the SATA, PCIe slot and M.2 that are AHCI and not NVMe, U.2 is a form factor that exclusively uses the NVMe protocol.
The infographic below will help you understand how all of the different form factors and protocol are found in various types SSDs and what the differences are in performance.