IIRC the extra pin on a 4 pin motherboard header may report if the fan has totally stopped, like a failure line, to tell the mobo to shut the CPU off. I've got an old 4 pin fan here from a '94 vintage ...

Didn't even realize that there was such a thing as a 4-pin PWM motherboard fan header until... yesterday. Anyways, I had planned on slapping a 120mm Scythe on the Ultra-120 that will be cooling my ...

The point of this guide is to show the latest and greatest in fan control technology on Intel Z270 motherboards and to help you understand what each brand has to offer in their high-end products. I ...