Passive 2-Phase Immersion Cooling of High Power GPUs: A Comparison Open Bath Immersion and Water Cooling for High Performance Computing (HPC) - (PPT)

摘要

1. Passive 2-phase immersion offers high efficiency relative to water cooling due in part to high boiling and condensation heat transfer coefficients but also to the elimination of the advective resistance. 1) The junction-to-fluid thermal resistance with immersion is 36% lower than the junction-to-water inlet resistance in the water-cooled IBM P575 [2]. 2) The junction-to-fluid thermal resistance with immersion is 33% lower than the junction-to-water inlet resistance attainable with direct-die water-cooled cold plates of [5]. It is 58% lower if a solder TIM is used for the immersion CPU module, a practice that may not be practical for water-cooled. 3) At 2 kW/liter condenser density (0.65 kW/liter system density), T_f - T_(H_2O, out) can be <2°C, optimizing thermal efficiency and the availability of heat for other purposes. With CPU power of 150W and T_j ～85°C, 60°C water could be heated to 70°C With T_j ～68°C, 30°C water returning from a comfort heating system could be heated to 57°C 2. Passive 2-phase immersion requires no node-level plumbing or large extended surfaces resulting in unprecedented power density. 1) A blade power density of 4 kW/liter was demonstrated 2) A system level power density > 1 kW/liter was demonstrated.