Improving Cache PerformanceAverage memory-access time = Hit time + Miss rate x Miss penalty (ns or clocks)•1. Reduce the miss rate, •2. Reduce the miss penalty, or•3. Reduce the time to hit in the cache. CSE 240ADean TullsenReducing Misses•Classifying Misses: 3 CsHow To Measure–Compulsory—The first access to a block is not in the cache, so the block must be brought into the cache. These are also called cold start missesor first reference misses.Misses in infinite cacheNl–Capacity—If C is the size of the cache (in blocks) and there have been more than C unique cache blocks accessed since this cache was last accessed.Non-compulsory misses in size X fully associative cache–Conflict—Any miss that is not a compulsory miss or capacity miss must be a byproduct of the cache mapping algorithm. A conflict miss occurs because too many acti e blocks are mapped to the same cache setNon-compulsory, non-capacity iactive blocks are mapped to the same cache set.missesCSE 240ADean Tullsen3Cs Absolute Miss RateCSE 240ADean TullsenHow To Reduce Misses?•Compulsory Misses?•CiMi?Capacity Misses?•Conflict Misses?•What can the compiler do?CSE 240ADean Tullsen
has intentionally blurred sections.
Sign up to view the full version.