The Cooler Master B-Series 500W, or B500, is a power supply that was developed exclusively for the European market. That means it’s only compatible with 230V, and not with 115V. It’s one of the reasons Cooler Master managed the extremely low price of € 43. A downside of this choice is that by leaving out 115V compatibility, Cooler Master couldn’t get a certification from the 80Plus agency, as they do their tests on 115V only. Cooler Master claims that, if 80Plus would also certify 230V PSUs, the B500 would be at an 80Plus Bronze level of efficiency.
The B500 also has two 12V rails that can supply 24A and 21A, respectively. That’s less than Antec’s PSU, but the total maximum capacity for both 12V rails is higher at 480W or 40A.
The Cooler Master power supply is not modular, which can’t be expected in this price segment. The motherboard cable is sleeved, like the Antec PSU. There are three molex connectors, six SATA connectors, and two 6/8-pin PEG connectors.
Again there’s a 12 cm fan inside the PSU, with the speed dependent upon the temperature. And there’s a power switch on the back.