A CPU has a 2-level cache hierarchy. The L1 cache has a hit rate of 90% and the L2 cache has a hit rate of 80%. What is the overall hit rate?
Q1. A CPU has a 2-level cache hierarchy. The L1 cache has a hit rate of 90% and the L2 cache has a hit rate of 80%. What is the overall hit rate?
Answer: 0.98
Explanation: Overall hit rate = L1 hit rate + (1 - L1 hit rate) * L2 hit rate = 0.9 + (1 - 0.9) * 0.8 = 0.98.