RAMZzz: Rank-Aware DRAM Power Management With Dynamic Migrations and Demotions
Main memory is a significant energy consumer which may contribute to over 40% of the total system power, and will become more significant for server machines with more main memory. In this paper, the authors propose a novel memory system design named RAMZzz with rank-aware energy saving optimizations. Specifically, they rely on a memory controller to monitor the memory access locality, and group the pages with similar access locality into the same rank. They further develop dynamic page migrations to adapt to data access patterns, and a prediction model to estimate the demotion time for accurate control on power state transitions.