IMPROVING THE THERMAL PERFORMANCE OF A FORCED CONVECTION AIR COOLED SOLUTION - PART 2: EFFECT ON SYSTEM-LEVEL PERFORMANCE

The heat sink assembly of an air cooled CPU is modified to improve thermal performance of the module-level solution.. This modification is employed in a dual-socket server that relies on system fans to move air for forced convection cooling of all heat generating components on the motherboard. Currently, in the data center industry, the focus is on reducing power consumption through application of energy-efficient cooling solutions. Fans installed in the server operate as a function of CPU die temperatures and represent a parasitic load that must be minimized. Improvement in system-level performance can be quantified in terms of reduced fan and server power consumption. The server is subjected to varying CPU utilizations and corresponding average fan speeds and power consumption are reported. Similarly, reduction in CPU junction temperature and server power at a given utilization can be computed by operating the fans at a constant speed. Difference in thermal performance and power consumption between the baseline and modified heat sink configurations was found to negligible when a TIM is applied. However, in the absence of a TIM, the modified assembly delivered as much as 24.4% reduction in CPU die temperature and 6.2% reduction in server power consumption. In addition, there is indiscernible variation in server power consumption between the baseline (with employment of TIM) and modified (with and without TIM application) heat sink assemblies. Thus, the modified configuration has possible applications in systems where a TIM may be undesirable or difficult to apply.