Profile - Based Adaptation for Cache Decay : A Technical Report UVA CS TR CS - 2004 - 14 April 2004

‘Cache decay’ is a set of leakage-reduction mechanisms that put cache lines that have not been accessed for a specific duration into a low-leakage standby mode. This duration is called the decay interval, and its optimal value varies across applications. This paper provides an extended discussion of the results previously presented in our journal paper [13]. It describes an adaptation technique that analytically finds the optimal decay interval through profiling, and shows that the most important variables required for finding the optimal decay interval can be estimated with a reasonable degree of accuracy using profiling. This work explicitly trades off the leakage power saved in putting both the ‘live’ and ‘dead’ lines into standby mode, against its performance and energy costs. It achieves energy savings close to what can be obtained with an omniscient choice of per-benchmark optimal decay interval.