Conflict misses are those misses which occur due to the contention of multiple blocks for the same cache set. Compulsory misses occur due to first time access to the block
1. compulsory miss/Cold Start Miss/First Reference Miss: the very first access to a memory Block that must be brought into cache
2.Conflict Miss/Collision Miss/Interference Miss: In addition to Compulsory and Capacity mises In Direct Mapped and in Set Associative Memories. when still there are empty lines in the cache, block of main memory is conflicting with the already filled line of cache, ie., even when empty place is available, block is trying to occupy already filled line. its called conflict miss
As per definition, if a block is removed due to another block and then when a future access happens and a miss results, then it is a conflict miss.
3.Capacity Miss: if the cache CANNOT contain all the blocks needed during the execution of a program, Capacity Misses will occur because of blocks are discarded and reterieved later.
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Definition given in GATE Question :
Conflict misses are those misses which occur due to the contention of multiple blocks for the same cache set.
Compulsory misses occur due to first time access to the block.
