Question

For a processor with primary and secondary caches, an instruction cache miss rate of 1%, a data cache miss rate of 5%, a instruction mix of 40% data accesses, a primary to secondary cache miss penalty of 10 cycles and a secondary cache to main memory miss penalty of 200 cycles and a secondary miss rate of 0.2%, what will be the contribution to total CPI from the cache misses (in decimal)

Answer 1

The answer is "0.306".

Step-by-step explanation:

The Primary to Secondary Memory Instruction miss cycle

`= I * 0.01 * 10 = 0.1 I`

Data miss cycles
`= I * 0.05 * 10 * 0.40 = 0.2 I`

The Secondary to main Memory Instruction miss cycle
`= I * 0.01 * 200 * 0.0002 = 0.004 I`

Data miss cycles
`= I * 0.05 * 200 * 0.0002 = 0.002 I`

Total memory stall cycle
`= ( 0.1 + 0.2 + 0.004 + 0.002 ) I =0.306 I`