This spec details the speed at which a drive sends and receives data. Sustained transfer rate is the total time required for system processing, head switching, and seek. This spec is the most accurate reflection of a drive’s true, real world performance. Be careful when comparing drives; in many cases, manufacturers will only display their drive’s burst transfer rate, or maximum transfer rate (a much higher figure reflecting only the movement of data into RAM). While this is a useful spec for many applications, it does not reflect the requirements of digital audio or video.