Comment by jeffbee
Yeah, oversized power supplies are also responsible for high idle power. "Gold" etc ratings are for their efficiency at 50%-100% rated power, not how well they scale down to zero, unfortunately. I have never owned a real GPU, I use the IGP or a fanless Quadro, so I don't have firsthand experience with how that impacts idle power.
Gold rating is down to 20%, Titanium is to 10% https://en.wikipedia.org/wiki/80_Plus#Efficiency_level_certi...