The Tyan Opteron mobo I got last summer has 4-pin headers for the CPU fans. I'm pretty sure they're the same as the ones described above. I've never actually seen a fan to plug into them (they are ...

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 ...

What is the best PC fan? All gaming PCs need good cooling to ensure consistent operation without any crashes or drops in the speed of its components. If you're building a new system, many PC cases ...