Operating System By Harris

Question

Assume the amount of memory on a system is inversely proportional to page fault rate. Each time when memory doubles the page fault rate is reduced by third. Currently system has 32mb of memory and page fault rate is 2% the main memory access time is 500ns. And effective memory access time is 300 μ sec. if the main memory is increased to 128 mb, then what would be the overall effective access time________.

Comments

yes  @satendra i also think 33.77 cannot be the answer.

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if the question is page fault is reduced to  ,then we have to take  2/900

and but here the question is page fault is reduced by  , so we have to take 8/900

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can anyone explain is pfst include mat

I always thought that pfst means time to transfer a page from disk to memory,so shouldn't we add mat in formula

EMAT=(1-p)*mat+p*(pfst+mat)

equivalent to

EMAT=mat+p*pfst