Antec's EarthWatts 500W
A PSU even Greenpeace could love

Antec's EarthWatts power supply is the tree-hugger of the bunch. As one might expect, it's billed as an energy-efficient model, complete with a leafy green logo. Antec also says it's the "most environmentally friendly power supply yet."

Don't let the eco-friendliness fool you, though; the EarthWatts may be available in wattages as low as 380W, but the model we have in-house today packs 500W, dual 12V rails, and a pair of PCIe power connectors for multi-GPU graphics configurations. Think of it as a turbocharged Toyota Prius—one with all the optional extras, including 80 Plus certification and active power factor correction.

The EarthWatts may be the equivalent of a pimped out Prius, but it certainly doesn't look the part. One could easily mistake the PSU for a budget generic model, and given the EarthWatts' $75 street price, you'd at least have the budget part right.

With only an 80mm fan pulling air at the rear, the EarthWatts features extensive venting along one of its internal panels to aid airflow. Unfortunately, that panel sits where most folks tend to stuff the bundle of unused power leads they end up with at the end of a system build. Users will have to be careful not to impede airflow to the vents too much.

Through our load testing, the EarthWatts maintains very consistent DC voltages across each rail. Antec doesn't nail the 3.3, 5, and 12V lines exactly, but voltages are all within 1% of where they should be, which is an impressive result.

The EarthWatts' AC ripple content is also consistently low on each rail. AC content averages around 10 millivolts—a drop in the bucket.

Our efficiency testing shows that the EarthWatts' 80 Plus certification is indeed justified. The PSU never dips below 80%, although efficiency does drop slightly when we apply our 100% load.