Question

can someone explain please when to use write back and when write through cache(hierarchical)...

Answer 1

my answer almost correct

write through means whenever there is change in cache imediately reflected in main memory

take an example:

for(i=1;i<=1000,i++)

{

i=i+100;

}

i want last update but in this write through every time main memory updating i.e 1000 times..disadvantage is every time updating

WRITE BACK:

in this only when concerned cache block replaced that time only it updated

 

give ma reply if u satisfied

Comments

But when to use write through?

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I need to know in calculating avg access time,  if in the question it is not mentioned that whether it is hirerachical access or write back access..then what we will consider?