Wide-load Efficiency
Efficiency is a bit scewed in favour of the Fractal at 100W and towards the Corsair and be quiet! at, say, 400W.
Evaluated over wide band from a 240V source, you ought to be getting about 90 per cent in most cases, meaning that a computer actually using 250W needs to pull about 280W from the mains. Gone are the days of 75-80 per cent efficiency.
Does the Fractal Ion SFX 500G hit its 80 PLUS Gold promise? Going by our numbers, the answer is yes.