In a computer system, memory-mapped access takes 100 nanoseconds when a page…
2018
In a computer system, memory-mapped access takes 100 nanoseconds when a page is found in TLB. In case the page is not in TLB, it takes 400 nanoseconds to access. Assuming a hit ratio of 80%, the effective access time is:
- A.
120 nanoseconds
- B.
160 nanoseconds
- C.
200 nanoseconds
- D.
500 nanoseconds
Attempted by 185 students.
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Correct answer: B
Given: Hit ratio H = 0.8
Miss ratio (1 − H) = 0.2
Access time on hit = 100 nanoseconds
Access time on miss = 400 nanoseconds
Effective Access Time (EAT) formula: EAT = H × (time on hit) + (1 − H) × (time on miss) Substitute values: EAT = 0.8 × 100 + 0.2 × 400 Calculation: = 80 + 80 = 160 nanoseconds Conclusion: The effective access time is 160 nanoseconds (160 नैनोसेकंड), which matches the option text "160 nanoseconds