Characterizing the dynamic reliable energy-efficient behavior of cache

Soft errors and energy consumption have both become the major design concerns for microprocessors, as a result of increasing transistor counts, shrinking feature size, lowering supply voltages. As the largest on-chip structures, cache memories face more serious reliability and energy challenges. The awareness of reliable energy-efficiency is greatly helpful to achieve a tradeoff between reliability and energy consumption with minimum costs for cache. In this paper, a new metric, MOPUETF (Mean Operations Per Unit Energy To Failures), is proposed to characterize the cache behavior in terms of reliable energy-efficiency. We compare three different metrics and MOPUETF is demonstrated to be more suitable for reliable energy-efficiency evaluation of cache. We also conduct a comprehensive characterization of dynamic behavior of Level-1 data cache (LID) MOPUETF. Experimental results show that LID MOPUETF exhibits different degree of variance for different programs, and fuzzy correlation exists between LID MOPUETF and several measurable performance metrics of processors. The dynamic reliable energy-efficient behavior of cache could be accurately captured in a larger space of performance metrics.