NeoPower is a high efficiency power supply series from Antec, being sold in the past as "HE" (High Efficiency). According to Antec, power supplies from this series have an efficiency of up to 85% (compare to less than 70% on regular power supplies), meaning less power loss – an 85% efficiency means that 85% of the power pulled from the power grid will be converted in power on the power supply outputs and only 15% will be wasted. This translates into less consumption from the power grid (as less power needs to be pulled in order to generate the same amount of power on its outputs), meaning lower electricity bills. Power supplies from this series – currently available on 380 W, 430 W, 500 W, 550 W and 650 W versions –feature a modular cabling system and a standard 80-mm fan on their rear side. We took an in-depth look on the 550 W model and tested to see if it could really deliver its rated 550 W or not.

http://www.hardwaresecrets.com/article/361