Reducing Leakage through Filter Cache

We evaluate the leakage reduction for both instruction and data cache in presence of drowsy or decay techniques. We discovered that a filter cache, traditionally used for reducing active power, can help reduce also leakage. The key idea is to reduce the lifetime of the lines that are in high-power state inside a leakage-saving cache. Power consumption has become one of the main concerns for designers, together with the performance. Caches account for the largest fraction of on-chip transistors in most modern processors. Therefore, they are a primary candidate for attacking the problem of the leakage. In average, for instruction cache 24\% improvement in leakage savings and 1.5\% in IPC (Instruction Per Cycle) can be achieved with respect to drowsy cache. For data caches, 5\% and 5.4\% improvement can be achieved respectively. Experiments have been performed also with decay cache showing fewer benefits.