Where do I connect the fans and why?

[natseb]

I have a rather basic question:

On my mobo (gigabyte GA-Z68XP-UD3) I have 4 connection for the fans:

2x 3 pins labeled as: SYS_FAN1 and PWR_FAN (are these running at full RPM no matter the load?)

2x 4 pins: CPU_FAN and SYS_FAN2 (are these controlled according to the load?)

I have two fans in the case and two on the CPU, what is the most efficient way of connection those to mobo?

Cheers

 

[o1die]

Use cpu fan and sys fan2 for the cpu fans or an adapter for the second 4 pin fan if needed, and the other two fan ports for the case fans. I use zalman "fanmate" series rpm adjusters for the case fans when they're not controlled by the bios smartfan settings.

 

[Raiddinn]

The CPU fan goes on CPU fan. If you have another CPU fan that also blows out the back I would put that on the other 4 pin.

I think I would probably use the 2nd 4 pin on the side fan. That is the one I would throttle according to temperatures the most. The top rear fan and the front fans can run at max speeds and its probably better if they do.

If you care about sound, just get the biggest slowest fans you can have and they will work fine. Big slow ones can still move tons of airflow and they tend to be much much quieter when they do it.

 

[gribs]

Raiddinn is spot on about the large fan size, for keeping noise minimal. Generally dont go lower than 120mm if you can. 200mm+ is a gentle whisper on max speed and a non-silenced 92mm CPU fan is loud enough to annoy me from across a room.

Even if you cannot affix the size of fan to your case, consider using a superglue or some other non permanent adhesive to affix them to the vents. Superglue has been a friend in customizing a few case and CPU fan layouts.

I've heard that you should always have more air blowing out than is coming in, so keep that in mind to maintain proper ventilation.