Saturday, October 1, 2011

New ASHRAE standards, energy efficiency, and HPC

The new ASHRAE standards, when vendors support them, allow for servers and storage that can be run continuously at a maximum of 113 degrees Fahrenheit. Your support contracts and warrantees are not voided when this is supported.

Dell is at the forefront of supporting these standards for the public. They have made public statements supporting these standards. Most of us have heard about the military running servers in the desert without air conditioning. Milspec is not for most IT organizations, but is paving the way for energy efficiency for the rest of us. It means in many places in the US, ambient air is plenty cold 100% of the time. No more cooling server rooms except as needed for people doing work in server rooms.

I have heard jokes in the past about hanging winter coats in server rooms in warm climates as people get very cold working for long periods in chilled rooms. Now the new joke is shorts, flip-flops, and tanktops on a rack by the server room door as we might start running these rooms much hotter.

How does this affect HPC?
Air cooling at any temperature is only good for racks holding up to about 20KW of power-using dense equipment. Any more than that and you just cannot get the heat out fast enough without help from a more dense material than air or by moving air so quickly that it is not cost effective. If I can run data centers on ambient air cooling, then running air cooled racks is getting cheaper and cheaper. Highly dense racks requiring chilled water or other solutions are becoming more expensive compared to these air cooled racks.

It has been the trend to try to use smaller and smaller server rooms, and get more and more dense. The benefits seem to now peak to 20KW/rack and go down from there. If you do not really need extreme HPC density for performance reasons, extra density is not cost effective.

Methods to retro-fit ambient air cooling into existing data centers are critically needed. There is not nearly enough action in the market in this area.

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