A computer system uses a cache memory with a hit ratio of 0.8. What is the average memory access time if the cache access time is 2 ns and main memory access time is 10 ns?
Q1. A computer system uses a cache memory with a hit ratio of 0.8. What is the average memory access time if the cache access time is 2 ns and main memory access time is 10 ns?
Answer: 3.6 ns
Explanation: Average memory access time = (hit ratio * cache access time) + ((1 - hit ratio) * main memory access time) = (0.8 * 2) + (0.2 * 10) = 1.6 + 2 = 3.6 ns.