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Consider a CPU that executes at a clock rate of 200MHz(5ns per cycle) with a single level cache. CPI execution i.e. CPI with ideal memory is 1.1. Instruction mix are 50% arithmetic/Logical, 30% load/store, 20% control instruction.

Assume the cache miss rate is 15% and a miss penalty of 50 cycles. The number of times cpu with ideal memory is faster when no miss occurs _______
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Ideal memory Cpu has CPI=1.1

Memory accesses/instruction=cycles required for instruction fetch + cycles required for execution

 =(0.5*1+0.3*1+0.2*1)+(0.5*0+0.3*1+0.2*0)=1.3

Total memory stalls=no of references * miss rate * miss penalty =1.3*0.15*50=9.75

CPI of cpu with miss operation=1.1+9.75=10.85

The number of times cpu with ideal memory is faster when no miss occurs =CPU with miss/CPU without miss=10.85/1.1=9.86
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