I need some basic electrical engineering type help in understanding how fan speeds are regulated. Most case fans these days come with motherboard headers or switches/sliders to control their speeds.

Am putting together a PC and have run into a problem with the MB/case. The case fan has a 3-hole connector and all system fan connectors on the MB are 4-pin. Case: Fractal Design Define R5 Black ...

If you've got an NVidia graphics card and it has a fan that sounds like a jet engine, or, if as in my case your fan starts at full speed when the computer boots but then turns off after 20 seconds or ...