Question

how is acces time on disk is defined?explain each component of access time.

Answer 1

The Access Time is the time required between the requests made for a read or write operation till the time the data are made available or written at the requested location. Normally it is measured for read operations. The access time depends on physical characteristics and access mode used for that device.

The disk access time has two major components:

(1). Seek Time :
The seek time is the time for the disk arm to move the heads to the cylinder containing the desired disk.

(2). Latency Time:
The Latency Time is the additional time waiting for the disk to rotate the desired sector to the disk head.


The sum of average seek time and latency time is known as the average access time.