April 04, 2011, 6:07 AM — Today's data center managers are struggling to juggle the business demands of a more competitive marketplace with budget limitations imposed by a soft economy. They seek ways to reduce opex (operating expenses), and one of the fastest growing -- and often biggest -- data center operation expenses is power, consumed largely by servers and coolers.
Alas, some of the most effective energy-saving techniques require considerable upfront investment, with paybacks measured in years. But some oft-overlooked techniques cost next to nothing -- they're bypassed because they seem impractical or too radical. The eight power savings approaches here have all been tried and tested in actual data center environments, with demonstrated effectiveness. Some you can put to work immediately with little investment; others may require capital expenditures but offer faster payback than traditional IT capex (capital expenses) ROI.
[ Unlearn the untrue and outdated data center practices in Logan G. Harbough's "10 power-saving myths debunked." | Use server virtualization to get highly reliable failover at a fraction of the usual cost. Find out how in InfoWorld's High Availability Virtualization Deep Dive PDF special report. ]
The holy grail of data center energy efficiency metrics is the Power Usage Effectiveness (PUI) rating, in which lower numbers are better and 1.0 is an ideal objective. PUI compares total data center electrical consumption to the amount converted into useful computing tasks. A not-uncommon value of 2.0 means two watts coming into the data center falls to one watt by the time it reaches a server -- the loss is power turned into heat, which in turn requires power to get rid of via traditional data center cooling systems.
As with all simple metrics, you must take PUI for what it is: a measure of electrical efficiency. It doesn't consider other energy sources, such as ambient environmental, geothermal, or hydrogen fuel cells, many of which can be exploited to lower total power costs. The techniques that follow may or may not lower your measurable PUI, but you can evaluate their effectiveness more simply by checking your monthly utility bill. That's where it'll really matter anyhow.