no of memory access

Question

how many memory access required to transfer a block to cache ?

suppose memory block is of size 16 word.

Comments

it is depend on what is your bus size.
Suppose if the bus size is of 4 words then it will take 4 mem access as one time you can transfer only 4 words from mem to cache. then 16/4 = 4 Mem access you required.

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Ok ,

When there is miss in cache we load block from main memory here i assuming only 2 level in memory hierarchy.

But

Average memory access time=

Cache hit time +miss ratio* memory access time.

It indicate when we miss we need only one memory access require but we need to transfer a block on miss .Can you elaborate  it?

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In those cases we assume that bus size is enoght to transfer a block from main memory to cache memory in one go only.

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Thanks