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If I have a Global miss rate of all caches of a total of 5.41% and the miss rate of a single level cache of 9.13%, how can I effectively calculate how much the second level cache miss rate need to be?

I found this where it says that the Local miss rate equals misses in a cache divided by the total number of memory accesses to this cache (Miss rate L2) and Global miss rate equals misses in a cache divided by the total number of memory accesses generated by the CPU (Miss Rate L1 x Miss Rate L2).

So if I divide 5.41% / 9.13% it equals 0.5926% for my second level cache. Is this assumption correct?

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You would only access the next level cache, only if its misses on the current one. Therefore the global miss rate is equal to multiplication of all the local miss rates.

0.0541    = L2 misses * 0.0913
L2 misses = 0.0541/0.0913 = 0.5926
L2 miss rate = 59.26%

In your answer you got the % in the wrong place.

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  • $\begingroup$ Always forget about the decimal. Thanks! $\endgroup$
    – Rick
    May 9 '17 at 0:44

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