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Thursday, February 14, 2008

First peek at Energy Star draft guidelines for server power efficiency

The Environmental Protection Agency (EPA) has released the first draft of the Energy Star power efficiency specifications for computer servers. Energy Star is following the strategy it used in developing power efficiency guidelines for electronic devices such as household appliances, wall warts and computers: It will first create a Tier 1 of relatively easily attainable power efficiencies, and then steadily raise the bar as customers and end- users of the equipment demand an Energy Star rating and make it a de facto standard.

Remember that Energy Star is completely voluntary. No will be forcing server vendors to meet it – except customers. For example, Tom Darby, manager of data centers for Texas Instruments, told me that the word is coming down from the top at TI that all server equipment purchased by TI in the future must meet Energy Star specifications.

The draft is at a very preliminary stage, with actual efficiencies still listed as “TBD”, although the loads points have been determined and are listed as 10, 20, 50, and 100%, with the power factor at these loads is also TBD except for 100% load, where it will be .9.

Why the wide load range? Server racks in data centers usually have redundant power supplies to ensure reliability, and currently most supplies operate at 50% of load, rather than one at full load and the other in standby. It’s just too difficult to get an ac-dc power supply to operate in standby and then spring instantly to life if its buddy should fail. At least, that’s the current status quo: Look for some new product announcements at APEC later this month for a couple of new power controllers being announced that allow interleaved architectures that shut down a phase for efficient operation at very low (<20%) loads.

Over the next several months, EPA will be testing existing server supplies to create a real-world data set to serve as the basis for the actual performance requirements in the second draft specification. The agency will also be working with industry groups such as Climate Savers and 80Plus to develop consistent test procedures and efficiency levels. This first draft has virtually no efficiency numbers, but serves more as a document of what needs to be determined and agreed upon by the industry as being current reasonable Tier 1 levels, with stretch goals to be set in Tier 2 specification.

(I currently just have a PDF of the draft; I’ll try to get a link to it on the Energy Star site as soon as it’s posted. Stay tuned for an update.)
UPDATE: You can view the draft here: http://www.energystar.gov/index.cfm?c=new_specs.enterprise_servers
...then click on the .pdf, "Draft 1 Computer Server Specification."

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