NVM Express

NVM Express, NVMe, or Non-Volatile Memory Host Controller Interface Specification (NVMHCI), is a logical device interface specification for accessing non-volatile storage media attached via PCI Express (PCIe) bus. "NVM" stands as an initialism for "non-volatile memory", which is commonly flash memory that comes in form of solid-state drives (SSDs). As a logical device interface, NVM Express has been designed from the ground up, capitalizing on the low latency and internal parallelism of flash-based storage devices, and mirroring the parallelism of contemporary CPUs, platforms and applications.

By its design, NVM Express allows levels of parallelism found in modern SSDs to be fully utilized by the host hardware and software. As a result, NVM Express reduces I/O overhead and brings various performance improvements in comparison to previous logical device interfaces, including multiple, long command queues, and reduced latency.

NVM Express devices exist both in form of standard-sized PCI Express expansion cards and as 2.5-inch form-factor devices that provide a four-lane PCI Express interface through the U.2 connector (formerly known as SFF-8639).SATA Express storage devices and the M.2 specification for internally mounted computer expansion cards also support NVM Express as the logical device interface.