MAT Flashcards
1
Q
What is the formula for Mean Access Time?
A
MAT = cacheAccessTime + (1 + hitRate) * mainMamoryAccessTime
MAT = c + (1 - h)*m
2
Q
What is the formula for Mean Access Time?
A
MAT = cacheAccessTime + (1 + hitRate) * mainMamoryAccessTime
MAT = c + (1 - h)*m
3
Q
What is the MAT if the hit rate is 100%?
A
The MAT would be the same as the cache access time. But this is impossible. Cache gets loaded only on misses. Main memory must be accessed sooner or later.
4
Q
What is the MAT if the hit rate is 0%?
A
This means nothing that the CPU wants is found in the cache. Time was wasted by looking in the cache. Cache can therefore actually slow down the CPU, by having nothing in it, or by having the “wrong words” in it. The MAT is the cache + main memory access time.
