X-bit labs has a roundup of power supplies. This is already the fifth part of their ATX PSU shoot out articles. In this edition they take a look at the Antec Neo HE 550 (550W), Antec Phantom 500 (500W), Antec TruePower 2.0 TPII-550 (550W), CoolerMaster iGreen Power RS-600-ASAA (600W), Corsair CMPSU-620HX (620W) and High Power HPC-560-A12S (560W).
In good old times PC power supplies used to have one power rail for each of the output voltages (+5V, +12V, +3.3V, and a couple of negative voltages), and the maximum output power on each of the rails was not higher than 150-200W. It’s only in some high-wattage server-oriented power supplies that the load on the +5V rail could be as high as 50A, i.e. 250W. This situation was changing as computers required ever more power and the distribution of power consumption among the different power rails was shifting towards +12V.