Consider an operating system capable of loading and executing a single sequential user process at a time. The disk head scheduling algorithm used is first come first served $FCFS$. If $FCFS$ is replaced by shortest seek time first $SSTF$ and the vendor claims $50%$ better benchmark results. What is the expected improvement in the I/O performance of user programs?

The system can execute only one sequential user process at a time.

So, at any time, there will be only one active I/O request from the user process.

Disk scheduling algorithms like $FCFS$ and $SSTF$ are useful when there are multiple pending disk requests.

Here, there is no queue of multiple requests to reorder.

Therefore, $SSTF$ cannot provide any real improvement over $FCFS$ for user programs in this case.

Expected improvement:

$0%$