(
Native
Command
Queuing) A feature of the SATA technology that reduces the number of read/write head movements in a hard disk. NCQ queues up read/write commands and executes them in the most efficient order.
Also for Solid State Drives (SSDs)
Command queuing is also used for SSDs because read and write instructions from the CPU can accumulate faster than even an SSD can handle them. The newer NVMe controller interface designed for SSDs increased the command queue an order of magnitude. While the common SATA/AHCI interface holds only 32 commands in one queue, NVMe supports 64K commands in 64K queues. See
AHCI and
NVMe.