Average memory access time

Question

I would like to know did I solve the equation correctly below

find the average memory access time for process with a process with a 3ns clock cycle time, a miss penalty of 40 clock cycle, a miss rate of .08 misses per instruction, and a cache access time of 1 clock cycle

AMAT = Hit Time + Miss Rate * Miss Penalty

Hit Time = 3ns, Miss Penalty = 40ns, Miss Rate = 0.08 AMAT = 3 + 0.08 * 40 = 6.2ns

Answer 1

Check the "Miss Penalty". Be more careful to avoid trivial mistakes.

The question that you tried to answer cannot actually be answered, since you are given 0.08 misses per instruction but you don't know the average number of memory accesses per instruction. In an extreme case, if only 8 percent of instructions accessed memory, then every memory access would be a miss.