I have a 1500W supply in one machine. It draws around 60% of that at peak load, putting it near the peak of the efficiency curve. The machine has two older gra

I have a 1500W supply in one machine. It draws around 60% of that at peak load, putting it near the peak of the efficiency curve. The machine has two older graphics cards, 16 drives, an E5-1650 and a fairly power-hungry motherboard (X99-E WS). Also, lots of 200MM fans - it is nearly silent at full load.