Asus P8P67 Pro

"1 x CPU Fan connector(s) (4-pin)
2 x Chassis Fan connector(s) (1 x 4-pin; 1 x 3-pin)
1 x Power Fan connector(s) (3-pin)"

ASRock P67 Extreme 4

"Fan Headers

1 x CPU fan
1 x CPU auxiliary fan
3 x Chassis fans
1 x Power fan

"Fan Control

CPU fans controlled jointly, 10 levels
Chassis fans controlled independently, 10 levels"

After finding out the P8P67 didn't have enough headers to control 3 chassis fans in total, and also - as a newbie not knowing the first thing about fan headers, taking it for granted it would be straight forward - only one for the cpu I started looking into other motherboards and lo and behold..

I understand automatic bios fan control is not something you can generally count on. I was just hoping I would have the ability to to finetune the front chassis fans beyond the initial 7v undervolting and at least have the ability to try to do as much as possible via the bios. The two chassis fan headers can be spun down via the Windows registry on the Asus, or so have I read: http://hardforum.com/showthread.php?p=1036834648.

Should I not worry about this stuff? I will most likely go with the Asus to honour what is available at the b&m that I am buying from. I could get 5v resistors for the front fans, I already plan to get a fanmate for the 120mm back exhaust, and I could also extend the undervolting to the rear fan on the Mugen. Also there are splitter cables I just dont know how that would work in practice..

I'm using an Asus Crosshair IV Extreme board and all three of its chassis fan headers share the same temperature sensor as the CPU, but have independent control levels. Setting them to the same levels as the CPU fan header is the same as using 4-way splitter in that instance.

Also, I've used PWM splitters before and they do work, but only one fan is able to send its RPM signal to the motherboard; multiple would cause a highly inaccurate reading. As long as you don't try to control too many fans from one header (I haven't exceeded 3) they won't be a problem.


If you're not satisfied with the motherboard's fan control or the utility that your manufacturer may include on the driver disc, The Speedfan program can take over the fan control of up to six 4-pin headers and control them individually according to your temperature preferences. And if your board isn't compatible with it, you can tell the creator the details of your board and he'll modify the program and release a beta version that does support it.

That's true as long as the fan headers have 4 pins and your fans have 4 wires (PWM controllable). 3 pin fan headers can only be read out, not controlled (AFAIK). I use Speedfan for my CPU fan and it works great. I don't think I've seen the fan go over ~280 rpm yet.

A few motherboards allow voltage control on 3-pin fans, but only on CPU headers.

Thanks guys, that is good to know about Speedfan. I guess thats why it feels kinda uncertain, between (and combining) splitters, pin adapters, pwm - which I dont have a full understanding of when it has bearing and not - and PWM fans being 3-pin mostly while the cpu header is 4 - effectively killing the PWM (?) using an adapter, I'm still a bit dumbfounded.

It depends of how the manufacturer have impemented the chipset fan control, not of the headers itself: on my mobos I can fully control most of the 3-pin fan headers with SpeedFan, and where the 4-pin headers are also voltage controllable (most MSI), I often use that way to reach lower rpm (lower than by PWM).

Erm, no, PWM is always 4-pin.

Was making the assumption from the Slipstream PWM and reading around: http://www.scythe-eu.com/en/products/fa ... 0-pwm.html

As said I dont know the first thing about pins, molex and headers and whats what, so I may have misunderstood something. Or its an exception.

Please, look at the fan: it has a four pins white socket, and four wire (orange, yellow, red and black) are coming from rotor and through the hub to the connector itself.

That is one of Scythe's 120mm Slip Stream PWM models. As you can see it has 4 wires. The orange one that 3-pin fans don't have allows speed control without changing the fan's voltage.

A PWM fan can be plugged into a 3-pin header but will not receive the PWM signal.

When looking for one, be advised that fans listed as having a "4-pin" header can mean they connect to a molex connector on the computer's power supply to draw voltage from the 5v or 12v line like this Silverstone model. They are not PWM.

http://www.newegg.com/Product/Product.aspx?Item=N82E16811999346