IBM’s POWER6 High Performance Water Cooled Cluster at NCAR: Infrastructure Design

The increased focus on green technologies and energy efficiency coupled with the insatiable desire of IT equipment customers for more performance has driven manufacturers to deploy liquid cooling technologies for cooling IT equipment. In April, 2008 IBM announced the world’s fastest UNIX server using unique water cooling technologies. The first system (eleven racks) was shipped and installed at The National Center for Atmospheric Research (NCAR) in Boulder, Colorado in May, 2008 to be used for research on climate change and severe weather. The POWER6 575 system utilizes water cooling to cool the processors as well as a water cooled rear door to remove 80% of the 60 kW heat load generated by each rack. This cluster of eleven racks with this highly efficient cooling system achieves a performance of 76 teraflops within a small footprint. This paper will describe the infrastructure required to support this cluster of racks including the chilled water cooling loop, water thermal storage tanks, and the 480 VAC power distribution system. The time response of the various potential failure modes in the water cooling system will also be described.