Under a load, the ArrowMax PSX-550AL-24 reported effifiencies that bounced between 0.98 and 0.99 (98% and 99%). You can't get much better than that, and a few months of pocketing the savings on your electric bill will contribute nicely to your next upgrade... The heat output during the testing agreed with the efficiency results, as the air coming out of the ArrowMax power supply felt about as warm as the room temperature.



Link: BigBruin