engineering computer science MCQ #24

In a 2-level memory hierarchy, the access time of the cache is 10 ns and that of the main memory is 100 ns. If the hit ratio is 0.8, what is the average access time?

engineering computer science MCQ #24

  1. Question 1

    Q1. In a 2-level memory hierarchy, the access time of the cache is 10 ns and that of the main memory is 100 ns. If the hit ratio is 0.8, what is the average access time?

    • A) 28 ns
    • B) 30 ns
    • C) 32 ns
    • D) 40 ns

    Answer: 28 ns

    Explanation: Average Access Time = Hit Ratio * Cache Access Time + (1 - Hit Ratio) * Main Memory Access Time = 0.8 * 10 + 0.2 * 100 = 8 + 20 = 28 ns.