Continued frequency scaling in 3D ICs through micro-fluidic cooling

Core scaling has largely replaced frequency scaling in general purpose microprocessors in the last decade. This is largely because of the high temperature and power dissipation associated with frequency scaling in traditional air cooled systems. In this paper we investigate how this trend changes when micro-fluidic cooling is added to a chip. Compared to traditional air cooling, micro-fluidic cooling can remove significantly more heat from the system, preventing thermal violations and reducing leakage power. This not only makes frequency scaling thermally feasible, but also increases the energy efficiency of higher frequency processors. Vertical integration of circuits (3D ICs) is a promising technology for facilitating a large number of cores, due to the limits on chip footprint size imposed by manufacturing yields. In this work we investigate the advantages of adding micro-fluidic water cooling to 3D stacked DRAM processors and show that such an approach can improve performance an average of 57.4% by making higher frequencies and more cores thermally feasible and improve energy efficiency 13.4% by reducing leakage power.