(4) Access time is the time delay or latency between a request to a computer, and the access being completed or the requested data returned. The key components that are typically added together to obtain the access time are: seek time, rotational latency, command processing time and settle time. With rotating drives, the seek time measures the time it takes the head assembly on the actuator arm to travel to the track of the disk where the data will be read or written. Rotational latency is the delay waiting for the rotation of the disk to bring the required disk sector under the readwrite head.