nvme

NVMe, short for Non-Volatile Memory Express, is a storage protocol and device interface optimized for solid-state drives that use PCI Express (PCIe) buses. It was designed to fully exploit the parallelism, low latency, and high bandwidth of modern non-volatile memory, offering a significant performance advantage over legacy interfaces such as AHCI that originated with spinning disks. NVMe drives are connected via PCIe and commonly come in form factors such as M.2, PCIe add-in cards, and U.2.

The architecture centers on submission queues and completion queues. The host submits I/O commands through one or more submission queues and receives completions via completion queues, enabling many operations to be in flight in parallel across multiple CPU cores. This multi-queue design minimizes overhead, reduces latency, and scales with hardware, delivering higher IOPS and throughput than older SATA-based SSDs.

NVMe over Fabrics extends the protocol to remote devices over network transports such as RDMA, Fibre Channel, or TCP, allowing centralized or distributed storage with the same programming model and performance characteristics as local NVMe devices.

Key features include namespace isolation, which partitions storage into independent environments, and Zoned Namespaces, which optimize writes for certain modern SSDs. The NVMe specification continues to evolve to improve efficiency, security, and manageability. NVMe is widely adopted in consumer high-performance drives and enterprise storage systems as the de facto standard for fast non-volatile storage.