Such heatsinks should help to cool the PSU at low fan speeds – for how else could you achieve noiselessness? On the other hand, a big portion of the air stream from the fan on the top of the case comes right to the plastic protective plate of the PFC board screwed up to the heatsinks, rather than on the heatsinks proper, and this PFC board doesn’t seem to require any cooling.

So, the active PFC device is made on a separate board and fits exactly into the crammed space between the heatsinks and the walls of the PSU. The most interesting thing about it is the logotype of Topower Computer. To all appearances it is Topower who makes power supplies for BeQuiet.

The regulation of the voltages in the BeQuiet unit is realized along the classic guidelines, as you can see on the screenshot. There’s a big group regulation choke behind the vertical board with the PWM controller. To the left of it, there’s a humbler choke of the dedicated +3.3v voltage regulator. Leftmost is a vertical cylindrical choke which is just part of an ordinary LC filter that smoothes out the pulsation of the output voltage.

The efficiency of the P4-450W PSU proves to be lower than that of the Antec, just over 80 percent at the maximum, but the power factor, thanks to the active correction, exceeded 0.95 even at a power load of 125 watts. Under a higher load it closely approaches the ideal, i.e. 1.