Hardware pre-fetching is a technique to improve cache performance. Hardware pre-

Question

Hardware pre-fetching is a technique to improve cache performance. Hardware pre-fetching of cache blocks represents a prediction on which blocks ought to be in the cache in the future. The pre-fetching can be correct and improve the performance while other times can be incorrect and hurt performance. Consider a system with one level of cache. Without hardware pre-fetching it shows a hit time of 1 cycle, a hit rate of 95% and a miss penalty of 100 cycles (for some application). With hardware pre-fetching (on the same application and with no change in hit times and miss penalties), we observe the following:

50% of memory accesses are better: hit rate = 97%

10% of memory accesses are worse: hit rate = 80%

the rest of the memory accesses are unchanged. With the parameters above, is it worth prefetching for this application? Please explain your answer.

Explanation / Answer

cache hit data found in cache.

To improve cache performance for this application yes its worth prefetching.

memory accesses=hit time +miss rate X miss penalty

                         = 100 cycles

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.