It was on July 20, 2007 that the Energy Star 4.0 computer specifications came into effect, which was most notable for including requirements for power supplies that met the standards of the 80 PLUS program. As of yesterday, all around requirements have become a little more strict as the new Energy Star 5.0 specs go into effect.

Any computer product (game consoles not included) manufactured on or after July 1, 2009 must meet the Version 5.0 requirements to qualify for the Energy Star certification, even if models were originally qualified under the 4.0 specifications. Making it a little tougher this time around, a computer's power supply must have an 85 percent minimum efficiency at 50 percent of the rated output and 82 percent minimum efficiency at 20 percent and 100 percent of rated output.

Full Version 5.0 Computer Specification (PDF)

Image Credit: EPA