Memory Hierarchy Q.81
- Option : B
- Explanation : Main Memory access time = 10–8 sec = (ta1)
Secondary Memo. access time = 10–3 sec = (ta2)
Access efficiency (n) = 80% = 0.8
Average Access time
tavg = n * ta1 = 0.8 × 10–3 sec
for Hit ratio H
tavg = H * ta1 + (1– H) * ta2
0.8 × 10–3 = H * 10–8 + (1 – H) * 10–3
0.8 = H × 10–5 + (1 – H)
H(1 – 10–5) = 0.2
H = 0.2/(1-10–5)
= 0.200002
= 20%
H = 20%
