# HAF XM case Fans



## ramisees (Dec 22, 2012)

Hi 
Just got a HAF XM case with a Asus P8Z77-V motherboard.

The mb has 4 pin fan connectors, the 3 case fans have a molex and 3 pin connectors. My question is,  can I use the mb fan connectors to drive the fans [ the 3 pins will fit into the 4 pin], or, should I use the molex connectors.


----------



## micropage7 (Dec 23, 2012)

4 pins (red,black,black,yellow) is for molex
3 pins is for board which run based on temp or setting
personally i dont recommended that


----------



## Hood (Dec 26, 2012)

I have the same mobo, and I use the sys_fan headers to control any fans that seem too loud at full power.  The headers are rated to 1 amp (12 watts), so no problem there running stock fans, even the 200/230mm fans only draw about a watt.  It all depends on how quiet you want it to be.  I have a total of 11 120/140mm fans in my Corsair 400R, and all I hear is a little air movement.  Only 2 of my fans are controlled by the mobo, the rest are quiet enough (I just bought 4 new Corsair fans).  So, the safest way is to use the 4 pin molex straight to the power supply, that way a $10 fan can't short out your fan header, and only use the headers if a fan is a little too loud at full speed.  You can use either Qfan control in the bios, or Fan Expert 2 in the software suite to control the speeds.


----------



## 1ceTr0n (Dec 26, 2012)

Motherboards can only adjust fan speeds if the fans have 4 pin PWM plugs like this and a BIOS gives you options to adjust fans speeds like the Asus ROG boards. These are typically used for CPU fan mobo headers








3 pin motherboard fan plugs will spin at full RPM no matter what unless the fan has a thermal diode on it for ambient temperature readings, the mobo doesn't have a clue about the fan other then the RPM speed on the 3rd wire and can't control it


----------



## erixx (Dec 28, 2012)

Most of the answers are a bit misleading.... 

The OP refers with 4-pin to 4-pin fan headers on the mobo not molex (which is a totally obsolete solution).

Asus boards have mostly 4 pin fan headers now, but 3-pin fans work fine on them, and even can be regulated for dynamic fan speed.

Yesterday I added 2 new Corsair 3 pin fans to my ROG mobo's 4 pin headers and they are dynamic.

Other brands like AsRock are a bit different and have "some" dynamic 3-pin headers, and some non dynamic. It may change from one mobo to another even within the same brand.

This situation is a shame, as the 4-pin fan offer is much smaller.


----------



## Hood (Dec 29, 2012)

*PWM vs voltage control*

My understanding is that the mobo can either use PWM to pulse the 4th wire to ground (turning it all the way off & on rapidly), or in the absence of the 4th pin, regulate voltage to the 2nd pin (12v +) down to 5-7 volts (on certain boards) while reading RPM from the 3rd pin.  I know my Asus P8Z77-V controls 3 pin fans, other brands or cheaper Asus boards may not.


----------



## erixx (Dec 29, 2012)

Yes Hood, I think that's it, and I didn't pretend to include your answer in the misleading answers department. Quite the contrary : )


----------



## 1ceTr0n (Dec 29, 2012)

Well screw you to erixx


----------



## Jetster (Dec 29, 2012)

erixx is correct


----------



## micropage7 (Dec 29, 2012)

oo.. i must be drunk when i read it 
thanks for correcting


----------

