Heterogeneous energy-efficient cache design in warehouse scale computers.

ABSTRACTEnergy efficiency is becoming the key design concern for modern warehouse-scale computer (WSC) systems, where tens of thousands of server processors consume a significant portion of the total power. Voltage scaling is one of the most effective mechanisms to improve energy efficiency at the cost of cell failures in large cache arrays. In this paper, we leverage the observation that there exists a diverse spectrum of tolerance to cache errors in large internet services to design a heterogeneous energy-efficient cache enforced by variable-strength error-correcting codes. The operating system may use the page coloring mechanism to control mapping applications to cache regions with differential reliability.