Pleas to improve datacentre power efficiency tend to be vague: consolidate to fewer and more efficient systems; use virtualisation to allocate resources based on need; and choose microprocessors, infrastructure components and system architectures that are built with power conservation as a key objective.
A dearth of meaningful metrics once led me to propose counting the cooling fans and reducing their number through attrition, even as capacity is added. Where there are fans, there's heat, and where there's heat, there's energy being wasted. Not very scientific, I realise.
I felt I had to suggest something, though, because the prevailing measure - performance per watt - is useless and misleading. The power consumption of a microprocessor die is a good measure of a chipmaker's effort to contribute to green computing, but it isn't the whole picture. For example, a power supply can waste considerable energy just converting AC to DC (something that I think should be done once per rack, but that's another story). As long as power conservation is solely the stuff of chipmaker tit-for-tat, we'll never make appreciable progress.
A non-profit consortium called the Green Grid has been formed to turn green intentions into the hard facts and formulas that underlie IT action plans. The Green Grid is taking a holistic approach that addresses all contributors to power inefficiency. And to help IT buyers identify vendors genuinely committed to saving power, the Green Grid is developing a logo program to label equipment that meets its criteria for minimum necessary power utilisation. The consortium has a blue chip roster of charter members including Intel, AMD, Sun, IBM, and VMware, along with support from the EPA and the Alliance to Save Energy.
These heavy hitters aren't getting together to play cardgames. In one of its first publications, entitled "Guidelines for Energy-Efficient Datacentres," the Green Grid lays out plainly what journalists like me have used hundreds of words to say: IT doesn't pay the electric bill, so it doesn't have the tools to determine how much power it's using and how much of that is wasted. The Green Grid proposes to close that gap, so its initial publications point to the need to pull together IT, facilities, electrical contractors, HVAC (heating, ventilating, and air conditioning), and vendors that sell power routing and battery backup equipment.