Oh I certainly knew that PS did not run the fan until a certain power level was reached, I was just surprised I never reached that power usage level. I guess I gave you that impression in my previous post, but the semi-fanless mode is the reason I bought that PS. I was just surprised that the fan never runs!

The reviews I read all showed that above ~25% power usage, the fans started. For a 660Watt PC, that is ~165Watts. I don't use that much power, ever, apparently. Even in summer, the fan does not run.

A lesson in that, SB and IB CPUs and boards don't use much power, even when OC'd. Plus I had no more than one HDD in the PC, the rest SSDs. Add to that a video card with no more than one power connector, and not gaming/stressing the video card, and all the fuss over not enough power is much ado about nothing. Also, IMO, PS load testers do not simulate the real world load PCs put on a PS at all.

Yet another example is my "old" X58 board and i7-930 CPU, with a X760, and GT240 video card. That PC's PS fan never starts too. Five case fans in that PC, two 200MM fans, plus CPU cooler fan, that PS is room temperature. Another bottom mount PS style case, I won't use anything else.

I don't feel bad at all, except that I now know I bought way more PS than I need. After fixing my friend's son's PC, with $400 video card, I confirmed what I suspected, high end video cards are power hogs! But why buy the Seasonic 400Watt fanless PS (basically a X650 with no fan), when I can get a 660Watt PS with a part time (HA!) fan.