This study goes beyond the common micro-channel cooling system composed of uniform parallel straight micro-channels. Due to the highly non-uniform power dissipation on a multicore processor, the micro-channel cooling system is designed to fit with the heat load on the multicore processor. By applying effective strategies and arranging key design parameters, stronger cooling is provided under the high power core area, and less cooling is provided under the low power cache area to save the precious pumping power. The well designed thermal-aware micro-channel cooling systems could effectively lower the hot spot temperature and temperature gradients on chip.
A three-stage approach to design thermal-aware micro-channel cooling system for multicore processor is developed. Two micro-channel cooling systems are specifically designed for a 2 core 150W Intel Tulsa processor and an 8 core 260W (doubled power) Intel Nehalem processor, to illustrate the design approach. The working fluid is single phase HFE7100. For the Tulsa processor, a strategy named strip-and-zone approach is used. The final design leads to 30kPa pressure drop and 0.094W pumping power while maintains the hot spot temperature to be 75 °C. For the Nehalem processor, a split flow micro-channel system and a widen-inlet strategy are applied. The final design takes 15kPa pressure drop and 0.0845W pumping power while maintains the hot spot temperature to be 82.8 °C. The design approach in this study provides the basic guide for the industrial applications of effective multicore processor cooling using micro-channels.