US servers guzzle more power than Mississippi

It's no secret that the servers behind every web 2.0 company, bank internet site and corporate email system are consuming ever larger amounts of power. But now a Lawrence Berkeley National Laboratory (LBNL) study has quantified exactly how much.

Servers in the US and their attendant cooling systems consumed 45 billion kilowatt-hours of energy in 2005. That's more than Mississippi and 19 other states, according to study author Jonathan Koomey, a scientist at LBNL and consulting professor at Stanford University.

And the computers' electricity appetite is still growing fast.

Koomey said: "Over a five-year period from 2000 to 2005, there has been about a doubling." Most of the growth is from the widespread adoption of lower-end servers costing less than $25,000, he said.

Server power demand has moved high up customer priority lists - especially with rising power costs and overstuffed data centres - and hardware makers are responding. Among the touted fixes are energy-efficient processors, power consumption caps, water cooling and consolidation of work from numerous inefficient low-end servers to fewer more powerful machines.

The study also estimated the world's server power consumption in 2005 at 123 billion kilowatt-hours. Based on the number of servers IDC forecasts to ship, the world's server power consumption will increase another 40 per cent over 2005 levels by 2010, Koomey said, assuming per-server power consumption stays at 2005 levels. But if server power consumption grows at past rates, 2010 power consumption will be about 75 per cent greater than 2005 levels, he said.

Chipmaker AMD - one of several hardware companies that has embraced energy efficiency as part of its sales pitch - funded the study. The study included supporting infrastructure such as data centre air conditioning and lighting but not other computing equipment such as storage arrays or network switches, Koomey said. That other equipment in total consumes about a third that of servers, he said.

Stephen Shankland writes for CNET News.com