Analysis of Refrigeration Requirements of Digital Processors in Subambient Temperatures

The total power consumption for high-performance computing systems is a serious concern for designers of integrated circuits and systems. It is well known that cooling the operating temperature results in reduced electronic power and/or speed gains. However, total power dissipation includes both electronic power and the refrigeration power. This study explores the optimal operating temperatures and the amount of total power reduction at subambient temperatures. This paper presents a realistic system-level model that includes both the electronic and the refrigeration systems. Analysis using the model shows the optimal temperature, and sensitivity to parameters of the electronic and refrigeration systems. For instance, a system with 50% electronic leakage and a minimum refrigeration coefficient of performance (COP) of 3.3, the optimized design operates at 8°C and offers a 44% power reduction over the noncooled design. Analysis also shows that temperatures near that of domestic freezers is nearly optimal for...