The Three Cs

Compulsory misses: These are cache misses caused by the first access to a block that has never been in the cache. These are also called cold-start misses.

Capacity misses: These are cache misses caused when the cache cannot contain all the blocks needed during execution of a program.

• Capacity misses occur when blocks are replaced and then later retrieved.

Conflict misses: These are cache misses that occur in set-associative or direct-mapped caches when multiple blocks compete for the same set.

• Conflict misses are those misses in a direct-mapped or set-associative cache that are eliminated in a fully associative cache of the same size. These cache misses are also called collision misses.