But I do need that fan running, just not at 736 RPM. With my setup, I do not have a dust problem so the PSU will always stay clean inside. I never liked a zero RPM design idea for just about any electronic components let alone an 850W power supply. If I leave it on default, the fan doesn't spin until it gets to almost 300W. At that point the temperature inside will be around 60C. I wonder at this point what the temperature of the switching transistors would be.