1.Compulsory misses(衝突性誤失):Also called cold start miss. A cache miss caused by the first access
to a block that has never been in the cache.
也稱為cold start misses,第一次存取未曾在cache內的block而發生的cache miss。

2.Capacity misses(空間性誤失):A cache miss that occurs because the cache, even with fully associativity, cannot contain all the block needed to satisfy the request.
因為在程式執行期間,cache無法包含所有需要的block而產生的cache miss。發生在一個block被取代後,稍後卻又需要用到。

3.Conflict misses(強迫性誤失):Also called collision miss. A cache miss that occurs in a set-associative or direct-mapped cache when multiple blocks compete for the same set and that are eliminated in a fully associative cache
of the same size.
發生在set-associative或direct-mapped caches,當多個blocks競爭相同的set。通常也稱作collision misses。

Memory hierarchy design challenges
 Design changeEffect on miss rate  Possible negative performance effect
 增加cache size 降低capacity misses可能增加access time 
 增加associativity 降低conflict misses可能增加access time
 增加block size 降低compulsory misses增加miss penalty

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