An integrated approach to reducing power dissipation in memory hierarchies

In recent years, both performance and power have become key factors in efficient memory design. In this paper, we propose a systematic approach to reduce the energy consumption of the entire memory hierarchy. We first evaluate an existing power-aware memory system where memory modules can exist in different power modes, and then propose on-chip memory module buffers, called Energy-Saver Buffers (ESB), which reside in-between the L2 cache and main memory. ESBs reduce the additional overhead incurred due to frequent resynchronization of the memory modules in a low-power state. An additional improvement is attained by using a model that dynamically resizes the active cache based on the varying needs of a program. Our experimental results demonstrate that an integrated approach can reduce the energy-delay product by as much as 50% when compared to a traditional non power-aware memory hierarchy.