Question

In a two level memory hierarchy, the access time of the cache memory is 12nanoseconds and the access time of the main memory is 1.5 microseconds. The hit ratio is 0.98. What is the average access time of the two level memory systems?

Answer 1

Answer:

Suppose 100 instructions are accessed from cache.

So, 98 instructions will take 12 ns × 98 and 2 instructions will take 1500 ns × 2.

So, average access time = (12 × 98 + 3000)/100 = 41.76 ns