Native Command Queuing (NCQ) is a technology designed to increase performance
of SATA hard disks under certain situations by allowing the individual hard
disk to internally optimize the order in which received read and write commands
are executed. This can reduce the amount of unnecessary going back-and-forth on
the drive's heads, resulting in increased performance (and slightly decreased
wear of the drive) for workloads where multiple simultaneous read/write
requests are outstanding, most often occurring in server-type applications.
However, the current technology actually slows down HD access in certain
applications, like games and sequential reads & writes, because of the added
latency induced by NCQ logic[1].