Maximising energy efficiency in 3D multicore systems: a formalised approach

Abstract

Three-dimensional integrated circuits (3D ICs) present an intriguing challenge for both circuit and system engineers due to their diverse cooling efficiency among the stacked dies. Several recent proposals advocate multiple techniques for thermal management of 3D ICs at different levels of the design, while operating within the confines of thermal heterogeneity. In this article, we analyse for the first time, the role of thermal heterogeneity on the energy efficiency of the system by incorporating temperature dependent leakage power. We develop a novel convex optimisation framework to optimise the energy efficiency in 3D ICs incorporating: (a) leakage aware thermal provisioning using temperature dependent full-chip leakage model, (b) heat flow in vertically stacked systems using a grid based compact thermal model and (c) a concrete application for workload provisioning in 3D multicore systems. Detailed simulation-based experiments with our proposed optimisation framework shows 5–17% improvement in the energy efficiency of a typical multicore system organised as 3D stacked dies.