A computer system has 2 levels of cache and main memory. Access times and miss rates...

 

Transcribed Image Text:

A computer system has 2 levels of cache and main memory. Access times and miss rates for an average program are given in the table below. The miss rates are local miss rates, i.e., the percentage of misses for the requests coming through to the specific level. Access time/ cycles Miss rate (local) L1 2 5% L2 5 60% Main memory 100 (a) Considering all memory accesses made by the CPU, what is the global miss rate of L1 and L2 cache? [2 marks] (b) Calculate the average memory access time (AMAT). [3 marks] (c) (d) The designer decides to add an L3 cache, which has an access time of 50 cycles, and a local miss rate of 40%. What is the new average memory access time? [2 marks] An experiment is performed on various cache block size configurations. It is found that CPU performance improves as the block size is increased. However, once the block size reaches a certain size, performance begins to decrease. Why might this be the case? [3 marks] A computer system has 2 levels of cache and main memory. Access times and miss rates for an average program are given in the table below. The miss rates are local miss rates, i.e., the percentage of misses for the requests coming through to the specific level. Access time/ cycles Miss rate (local) L1 2 5% L2 5 60% Main memory 100 (a) Considering all memory accesses made by the CPU, what is the global miss rate of L1 and L2 cache? [2 marks] (b) Calculate the average memory access time (AMAT). [3 marks] (c) (d) The designer decides to add an L3 cache, which has an access time of 50 cycles, and a local miss rate of 40%. What is the new average memory access time? [2 marks] An experiment is performed on various cache block size configurations. It is found that CPU performance improves as the block size is increased. However, once the block size reaches a certain size, performance begins to decrease. Why might this be the case? [3 marks]