a$.$ Suppose that we are considering an enhancement to the processor of a server system used for web serving. The new CPU is $10$ times faster on computation in the web serving application than the original processor. Assuming that the CPU is idle for $20\%$ of time, does computation for $30\%$ of time and is waiting for I$/$O for $50\%$ time, what is the overall speed up in this case?

$[2$ Marks$]$

b$.$ Computer A executes the MIPS ISA and has a $3$Ghz clock frequency. Computer $B$ executes the $86$ and has a $4$ Ghz clock frequency. On average, programs execute $2$ times as many $86$ instructions than MIPS instructions. For Program P$1,$ Computer A has a CPI of $3$ and Computer B has a CPI of $4.$

Which computer is faster for P$1?$ What is the speedup? $[2$ Marks$]$

c$.$ A program has $10\%$ divide instructions. All non$-$divide instructions take one cycle. All divide instructions take $50$ cycles.

a$.$ What is the CPI of this program on this processor? $[1$ Mark$]$

b$.$ What percent of time is spent just doing divides? $[1$ Mark$]$

c$.$ What would the speedup be if we sped up divide by $5x?[1$ Mark$]$