Here is a story from slashdot about Benchmarking Power-Efficient Servers:

Benchmarking Power-Efficient Servers

Posted by kdawson on Tuesday August 21, @10:22AM
from the fair-and-balanced dept.

modapi writes “According to the EPA, data centers — not including Google et. al — are on track to double power consumption in the next five years, to 3% of the US energy budget. That is a lot of expensive power. Can we cut the power requirement? We could, if we had a reliable way to benchmark power consumption across architectures. Which is what JouleSort: A Balanced Energy-Efficiency Benchmark (PDF), by a team from HP and Stanford, tries to do. StorageMojo summarizes the key findings of the paper and contrasts it with the recent Google paper, Power Provisioning for a Warehouse-sized Computer (PDF). The HP/Stanford authors use the benchmark to design a power-efficient server — with a mobile processor and lots of I/O — and to consider the role of software, RAM, and power supplies in power consumption.”

This sounds very good if you can try it out.