Question

I-cache miss rate is 2%, D-cache miss rate is 5%. Miss penalty is 100 cycles. Base CPI is 2 CPI. If load and store are 20% of instructions, what is the actual CPI?

Answer 1

5

Step-by-step explanation:

Given that:

i - cache miss rate = 2%

D-cache miss rate = 5%

Miss penalty = 100 cycles

Base CPI = 2 CPI

If load and store are 20% of instructions

i - cache = 2% * 100 = 0.02 * 100 = 2

D - cache = 5% * 20% of instructions * 100

D - cache = (0.05 * 0.2 * 100) = 1

Base CPI = 2

Hence, Actual CPI :

i - cache + D-cache + Base CPI

(2 + 1 + 2) = 5