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 ...

The only caveat is if your mobo has a few 3-pin connectors all in a row with no space in between. In that case there won't be room for the extra pin, except for the 3-pin connector on one end.

“The EMC2101 from Microchip/SMSC is a fan controller with temperature monitoring, and it will take care of all of that for you with a programmable PWM output and tachometer input. Four pin PC ...

This PWM compliant fan hub is compatible with 3 pins and 4 pin fan, which covers 100% of the PC fans available. All of the fan connectors are actually based on 4 pins and thus have full PWM ...