Gateforum Test Series: CO & Architecture - Cache Memory

Question

Isn't the answer 18 ns but 36 ns is provided as a valid answer.

Comments

https://gateoverflow.in/51806/what-average-acess-time-system-considering-only-memory-cycles

this question may help you

check the comment of sushant

 

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Hmm, got it. Thanks

Answer 1

No answer should be 36ns

see

TAT(total access time)= 0.8*( (0.9*10) + (0.1*110) ) +0.2*(100)

       =0.8(9+11)  +20

       = 20*8 +20

       =16+20 =36ns

note: here write through policy is used when writing in cache we need to update Main memory as well which can be done in parallel  so for writing we need only max(cache access time, main memory )

Comments

Nice Thank You