June 22–26, 2014
Leipzig, Germany

Presentation Details

Name: Evaluation of the Impact of Direct Warm-Water Cooling of the HPC Servers on the Data Center Ecosystem
Time: Thursday, June 26, 2014
09:30 am - 10:00 am
Room:   Hall 5
CCL - Congress Center Leipzig
Breaks:07:30 am - 10:30 am Welcome Coffee
Speaker:   Radosław Januszewski, PSNC
Abstract:   The last 10 years we have witnessed a rapid growth of the computational performance of the servers used by scientific community. This trend was especially visible in the HPC scene, where the price per FLOP decreased, while the packing density and power consumption of the servers increased. This in turn changed significantly challenges and costs of keeping the environmental conditions. Currently operational costs, mainly the power bill, over the lifetime of a computing system overshadow the acquisition costs. The overhead on the consumed power introduced by the need of cooling down the systems may be as big as 40%, therefore optimizations in this area should be beneficial in terms of both economy and efficiency. There are many approaches for optimizations of the costs, mainly focusing on the air cooling. Contrary to these have we decided to scrutinize a different approach. We planned to use warm (up to 45C inlet temperature) as the cooling medium for computing cluster and check if using this way of cooling can introduce significant savings and, at the same time, we can simplify the cooling infrastructure making it more robust and energy efficient. Additionally, in our approach we tried to use variable coolant temperature and flow to take maximum advantage of so called free cooling, minimizing the power consumption of the server-cooling loop pair. To validate the hypothesis PSNC built a customized prototype system which consists of of hybrid CPU and GPU computing cluster, provided by Iceotope company, along with customized, highly manageable and instrumented cooling loop.
In the paper we analyze the results of using our warm-water liquid cooled system to see if and, if it is the case, what are the positive and negative consequences for the data center ecosystem.

Radosław Januszewski, PSNC; Norbert Meyer, PSNC; Joanna Nowicka, Poznan University of Technology