Cooling – making efficient choices White paper update 2016

Due to the increasing role of energy costs and growing heat density of servers, cooling issues are becoming highly challenging and very important. While power consumption is recognised to be one of the main challenges for future HPC systems, attention to this issue tends to be limited to the power consumed by the computer hardware only, leaving aside the increase in cooling power required by more densely packaged, highly integrated hardware. The information presented herein is a result of data analysed and collected in a process of distributing a detailed survey among PRACE partners. The PRACE 3IP Pre-Commercial Procurement (PCP) contributes to the development of energy efficient HPC technologies and architecture, targeting improved cooling and energy efficiency of the overall system along with fine scale monitoring of energy consumption. The methodology designed for this PCP to evaluate energy efficiency could be re-used for other HPC infrastructure procurements, allowing for a better view of the TCO of the future system. This paper provides an overview of traditional technologies cooling and devices currently used in modern HPC data centres as well as some innovative and promising solutions adopted by some PRACE partners that may pave the way for future standards. The advantages and disadvantages of each described solution are discussed and general recommendations are provided as to which aspects HPC centres should take into account when selecting and building a cooling system