Tagged Command Queuing
Tagged Command Queuing (TCQ) is a feature that was originally introduced with the SCSI -2 and later also with the ATA -4 specification. Similar to the Native Command Queuing (NCQ) function of the S-ATA II specification, it accelerates the read / write processes for hard disks .
Are there e.g. If, for example, there are several read requests in the command queue , each request is first provided with a tag that corresponds to the place in the queue. Then the hard drive controller rearranges the requests so that the total time of all requests is minimized.
See also: Native Command Queuing