More Practice with Modification Analysis $$ from $[117]$

Consider an interactive system with a CPU and two disks. The following mea$-$ surement data was obtained by observing the system:

r r r r r r r r r

$($a$)$ Give asymptotic bounds on throughput and response time as a function of the number of terminals.

$($b$)$ Now consider the following modifications to the system:

$1.$ Move all files to the fast disk.

$2.$ Replace the slow disk by a second fast disk.

$3.$ Increase the CPU speed by $50\%($with the original disks$).$

$4.$ Increase the CPU speed by $50\%$ and balance the disk load across the two

fast disks.

For each of these four modifications, compute and graph the effects on the original system. Explain in words the effect when the multiprogramming level, N $,$ is small and when N is large.