CoMETC

Abstract

We introduce a Coordinated Management of Energy, Thermal, and Cooling (CoMETC) technique to minimize cooling and memory energy of server machines. State-of-the-art solutions decouple the optimization of cooling energy costs and energy consumption of CPU and memory subsystems. This results in suboptimal solutions due to thermal dependencies between CPU and memory and the nonlinearity in energy costs of cooling. In contrast, we develop a unified solution that integrates energy, thermal, and cooling management for CPU and memory subsystems to maximize energy savings. CoMETC reduces the operational energy of the memory by clustering active memory pages to a subset of memory modules while accounting for thermal and cooling aspects. At the same time, CoMETC removes hotspots between and within the CPU sockets and reduces the effects of thermal coupling with memory in order to minimize cooling energy costs. We design CoMETC using a control-theoretic approach to guarantee meeting these objectives. We introduce a formal thermal and cooling model to be used for online decisions inside CoMETC. Our experimental results show that CoMETC achieves average cooling and memory energy savings of 58% compared to state-of-the-art techniques at a performance overhead of less than 0.3%.