Question

What is the average I/O time if a 3600-RPM disk transfers an 800 KB block with a 7 ms average seek time, a 100 MB/sec transfer rate, and a 0.17 ms controller overhead?

Answer 1

Qo.

ANS:

The formula for Average I/O Time(Disk Access Time )

Disk Access Time = Seek Time + Rotational delay + Transfer time + Controller overhead

In the question given is:

Seek Time=7 ms

Controller overhead =0.17 ms

So

Disk Access Time= 7 + (0.5*60*1000/3600) + (800*1024/100 * 2²⁰) + 0.17

Disk Access Time= 7 + 8.33333 + 0.0078125 + 0.7

Disk Access Time= 16.0411 ms

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THANKS!!