One of the current trends in data center hardware energy efficiency is the burgeoning availability of on-demand power distribution and cooling devices. The basic idea in this model is that the distribution of power and cooling throughout the datacenter should be a dynamic process with it being applied as and where needed.
Obviously, this helps with the overall efficiency of the datacenter, and should be considered part of the overall model for future datacenter design. This summer's heat wave has certainly put a strain on the cooling systems of US datacenters, and overall, it has been surprising how few heat related outages have actually been reported.
But at Purdue's High Performance Computing datacenter, heat is more of a problem than in most corporate datacenters. The nature of the jobs that run on their supercomputers is such that if the computer or some major subset of nodes goes down, the entire job has to be started from scratch, which is no trivial matter, as some of the computational analysis run at the site can take months to complete, running 24/7.
Since the amount of heat that is generated by 15,000 processors is significant, and runaway temperatures can actually damage the hardware, the Purdue supercomputer datacenter starts setting off warnings at an ambient temperature of 82 degrees and starts shutting itself down at 90. But one of their system administrators thought he had a better answer.
Patrick Finnegan came up with the idea of using the capabilities in the AMD and Intel processors to throttle down the CPU performance (of 8000 processors) in order to reduce the amount of waste heat that was generated by the supercomputer. The nature of the datacenter meant, however, that the process couldn't be tested; the first time it would be used was when it was actually needed.
Needless to say, the process worked, and Purdue has made it available to other users of distributed computing systems running Linux (it was written for Redhat) from their Folio Direct site.
So what does the corporate user learn from this? A little imagination can go a long way, and there is more than one way to manage the environment in your datacenter.