Question

Consider an operating system capable of loading and executing a single sequential user process at a time. The disk head scheduling algorithm used First Come First Served (FCFS). If FCFS is replaced by Shortest Seek Time First (SSTF), claimed by the vendor to given 50% better benchmark results, what is the expected improvement in the I/O performance of user programs?

Answer 1

The I/O performance of a user program determined by many input and output devices not only by the disk. When we uses FCFS and replace it by SSTF it improves only disk driver performance not the entire I/O performances. So I/O improvement performance of user program is 0%.