The US Environmental Protection Agency and hardware vendors are developing a protocol to help server buyers compare different products by performance per watt.

Effectively outlining how much computing bang they're getting from each watt of electricity, both within and between vendors' product ranges, will provide a valuable comparison that is hard to do today.

By next week, the EPA will begin distributing a final draft of the protocol, which outlines a way to measure how much power is used by a server tested against transaction-based benchmarks, such as the number of Web pages served per hour, according to several people involved in the effort.

"If you are a server buyer and you want to compare the energy performance of the servers from different vendors, you have a hard time doing that. The reason is that each manufacturer gives data in their own way, and the data given is not consistent between the vendors," said Jonathan Koomey, who heads the group developing the protocol and has advised the EPA on other energy issues. He is also a consulting professor at Stanford University and a staff scientist at Lawrence Berkeley National Laboratory

The inability to compare how much energy servers use "is a problem for the customers of these manufacturers," said Koomey. Vendors recognise customer concerns "but until now they haven't known what to do about it." Koomey believes some vendors may move quickly to use the server protocol, but large-scale adoption will take time - and customer insistence. "It's going to take some pressure by the customers; if the customers really demand it, the manufactures will change really fast."

One large customer that is already asking for energy data from vendors is Lehman Brothers. "I believe that standardised benchmarking will actually create a more competitive environment amongst vendors, thereby spurring on additional innovations for power efficiencies - not only at power supply levels but CPU, storage and memory levels as well," said Salmon. "Even a small energy savings of 25, 50 watts per server can translate into significant reductions in yearly operating expenses in addition to providing the ability to extend the life of existing data centres and their infrastructures."

Salmon also said that over the past two years, Lehman has reached out to all its hardware vendors, either directly or via peer groups, and "expressed our desire to see more products that are energy efficient without significant impact to processing performance. If a standardised protocol were to be established by any government or industry entity, Lehman Brothers would encourage or require our hardware vendors to adopt such a reporting protocol."

Hardware vendors participating in the effort include HP, Sun Microsystems, Dell, AMD, Intel and IBM. The initial measurement protocol is aimed at 1U and 2U servers, and may be eventually broadened to include larger and more complex servers as the measurement evolves.

Original reporting by Computerworld