Plugging in case fans

[archie456]

Hi,

I'm putting together my HTPC.

I've noticed that the case fan (the fan from the Silverstone LC02 case) has a three pin socket on the end of it.

Whilst the motherboard SYS_FAN socket has four metal legs.

Now the three holes in the plug will fit the 4 prong connector- one is just left unconnected, and there are little plastic lugs on the back which force you to use the first three prongs.

So would I be right in assuming I can just plug the fan cable into the SYS_FAN socket with one prong unused and everything will be OK??

I assume that the unused one is speed control or something like that.

I'd appreciate some advice.
Cheers.

 

[Trollslayer]

Yes, the fourth prong is for speed control by varying the voltage.
This just means your fan will run at full speed.

 

[RBJTech]

A 4 pin header allows the fan to be controlled with PWM - and intel specification ( basically stops 'stalling' at very low speeds) - The above post is incorrect though, a 3 pin header will allow fan speed control, but it will be via voltage rather than PWM.

In short, 3 pin will be fine and your mobo will likely control the speed of the fan based on case 'mobo' temp with an onboard sensor.