If a cache memory has a hit ratio of 0.8 and the access times for cache and main memory are 10ns and 100ns respectively, what is the average access time?
Q1. If a cache memory has a hit ratio of 0.8 and the access times for cache and main memory are 10ns and 100ns respectively, what is the average access time?
Answer: 28ns
Explanation: Average access time = (hit ratio * cache access time) + ((1 - hit ratio) * main memory access time) = (0.8 * 10) + (0.2 * 100) = 8 + 20 = 28ns.