New CPU cooler fan connection

[Helium_Junkie]

My recent purchase has a 4 pin fan connector, but my controller only has 3 pins. Which pin doesnt need to be connected (I presume one is for speed feedback or some such).

 

[hp7909]

Which HSF is it? Ask because some, like Arctic Cooling Freezer 64 Pro, the 4-pin connector is grooved to guide it in on a 3-pin header. If doesn't have, then line-up the black wire with the ground/GND pin of the mobo connector.