CO: William Stalling: Write Through and Write Back, which is more efficient.

Question

According to my calculation, the time required in write back is 240ns and for write through it should be 1920ns. Is it correct or not?

Comments

no actually in write back protocol you also do unnecessary writes because if only one word is changes you have to write the whole block unlike write through. Thats why this question is asked bcz
in case of 1 word written, write through will take 30 but write back will take 240ns
in case of 2, write through will take 60 but write back will take 240ns
in case of 3, write through will take 90 but write back will take 240ns....and so on
in case of 8, write through will take 240 but write back will take 240ns,

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no actually in write back protocol you also do unnecessary writes because if only one word is changed you have to write the whole block unlike write through. Thats why this question is asked bcz
in case of 1 word written, write through will take 30 but write back will take 240ns
in case of 2, write through will take 60 but write back will take 240ns
in case of 3, write through will take 90 but write back will take 240ns....and so on
in case of 8, write through will take 240 but write back will take 240ns,

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so , does it means that write through is more efficient than write back???