Partially-Forgetful Memories: Relaxing Memory Guard-bands for Approximate Computing

While the memory subsystem is already a major contribu-tor to energy consumption of computing platforms, the guard-banding required for masking the effects of ever increasing manufacturing variations in memories imposes even more energy overhead. In this paper, we explore how Partially-Forgetful Memories can be used by exploiting the intrinsic tolerance of a vast class of applications to some level of er-ror for relaxing this guard-banding in memories. We discuss the challenges to be addressed and introduce Relaxed Cache as an exemplar to address these challenges for partially-forgetful SRAM caches. Preliminary results show how adapt-ing guard-bands to application characteristics can help the system save significant amount of cache leakage energy (up to 74%) while still generating acceptable quality results. 1