For system builders, NCQ offers a way to easily scale high-capacity Serial ATA disc for use in desktop PCs to high performance PCs, workstations and entry servers--and at just pennies per Gigabyte.
NCQ drives have an internal queue where these unsent commands, along with mechanisms that track outstanding and completed portions of the workload, are rescheduled or re-ordered.
NCQ reduces the rotation latency by processing more IOPS with fewer disc revolutions.
NCQ is a highly efficient protocol implementation of tagged command queuing.
Unlike TCQ, Serial ATA NCQ reduces the overhead a queuing algorithm can create.
NCQ reduces the average number of interrupts per command to as few as one.
NCQ uses First Party DMA to allow the drive set up Direct Memory Access (DMA) operation for a data transfer without host software intervention.
To make it possible for Serial ATA to take advantage of NCQ, two special NCQ commands--Read FPDMA Queued and Write FPDMA Queued--were developed.