Leo also said users have to play a role. Vendors "need to take a real-world approach and meet with the users" and not develop a standard without user input, he said.

Dave Douglas, vice president for eco-responsibility at Sun Microsystems Inc., said the protocol will have to be paired with an existing benchmark. And while those benchmarks may not be real-world, most users have enough experience to know how a benchmark might compare with actual workloads.

In general, officials at Sun, IBM and Hewlett-Packard Co. all support the measurement protocol. But they said it's too early to know just when it will be ready for customer use.

Christian Belady, distinguished technologist at HP who has been directly involved in the effort, believes a uniform measurement protocol is inevitable because of customer concerns about saving power. "Ultimately, we believe it's going to be something that we have to do," he said.