engineering computer science MCQ #179

A cache has a hit ratio of 0.9, cache access time = 1 ns, main memory access time = 10 ns. What is the average access time?

engineering computer science MCQ #179

  1. Question 1

    Q1. A cache has a hit ratio of 0.9, cache access time = 1 ns, main memory access time = 10 ns. What is the average access time?

    • A) 1.9 ns
    • B) 2 ns
    • C) 1.1 ns
    • D) 1 ns

    Answer: 1.9 ns

    Explanation: Average access time = (hit ratio * cache access time) + ((1 - hit ratio) * (cache access time + main memory access time)) = 0.9*1 + 0.1*10 = 0.9 + 1 = 1.9 ns.