How do you call a 610 W power supply that is labeled as a 660 W product but can only deliver half of this continuously at a room temperature of 45º C and will reach the market costing between USD 120 and USD 130? Because the word we have for that is unpublishable.

The funny thing is that Cooler Master eXtreme Power Plus 460 W – which is also manufactured by AcBel Polytech – costs only USD 40 and is a better product than iPower 660.

AcBel Polytech iPower 660 is a textbook example of a power supply that was labeled at 25º C. The problem is that no computer in the world works internally at such low temperature and semiconductors lose their capability of delivering current as the temperature increases, a phenomenon called de-rating.

Some people think that as long as a power supply can meet the manufacturer’s published specs it is a good product. This is a perfect example of why we disagree with this mentality: what’s the use of a 610 W power supply than can’t deliver enough power to your system when it is hot?

The only good thing we could say about this power supply that it could be worse: it could have exploded or burned, but at least over current and over power protections are working fine.

If you are looking for a good power supply on the 600 W range there are several good options on the market, with OCZ StealthXStream 600 W providing the best cost/benefit ratio among the models we’ve reviewed so far. If you are a mainstream user maybe you don’t even really need 600 W and a good power supply like Antec EarthWatts 500 W, Corsair VX450W or SilverStone Strider ST50F 500 W should be enough if you are looking for a product with good cost/benefit ratio.

Our conclusion is pretty obvious: stay away from this power supply!