Skip to content
GATEiit

GATE CSE 2022 Q33: Minimum hit rate after a cache optimisation

Question

A cache memory that has a hit rate of 0.8 has an access latency 10 ns and miss penalty 100 ns. An optimization is done on the cache to reduce the miss rate. However, the optimization results in an increase of cache access latency to 15 ns, whereas the miss penalty is not affected. The minimum hit rate (rounded off to two decimal places) needed after the optimization such that it should not increase the average memory access time is _____________.

Try it: numerical answer: type the value

Numerical answer. No negative marking.
Show answer and explanation

Answer: 0.85 (official GATE 2022 final answer key)

Concept used: Average memory access time = hit time + miss rate × miss penalty.

First step: Before: 10+0.2×100=3010 + 0.2 \times 100 = 30 ns. Solve 15+(1−h)×100≤3015 + (1 - h) \times 100 \le 30 for hh.

Full step-by-step solution

Detailed working, common mistakes and linked mock tests will be available with a free GATEiit account. Log-in is coming soon.

Share this question

WhatsAppDownload image

Source: official GATE 2022 CS question paper and final answer key, organised by IIT Kharagpur. Question paper · Answer key

More Computer Organization and Architecture PYQs

PracticePractise Computer Organization and Architecture questions →Full paperAll GATE CSE 2022 questions →