Analysis on the Impact of the Cooling Water Temperature on the Oakforest-PACS System and Facility
TimeTuesday, June 23rd2:55pm - 3pm
DescriptionHot water cooling approach  has been established as one of the standard techniques to improve the energy efficiency of modern HPC/Data Centers. However, to fairly evaluate its efficiency, there is a need to take into consideration not only the energy reduction of the cooling facilities, but also some possible negative impacts on the HPC system side. In this poster, we present some preliminary results of an investigation using the Oakforest-PACS (OFP) system and facility using three temperature cases (9oC, 12oC, and 18oC). . As preliminary analysis results, we could confirm that better PUE (1.25 -> 1.20 -> 1.18) and COP (4.26 -> 6.23 -> 8.72) can be obtained by using higher temperature settings. However, we could also perceive some performance degradation on the HPC system nodes, due to the frequency throttling mechanism, when using high temperature settings (18oC). A more detailed analysis is part of our future works, which also include the impact on the energy consumption of the HPC system side.
 S. Zimmermann, et al., Aquasar: A hot water cooled data center with direct energy reuse. Energy. 43. 237–245.