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Help with chassis/power fan connectors on motherboard

Gary Seven

New member
Feb 17, 2012
Hello everyone.

I am preparing the following build:

1. Case: Fractal Design Define R3
2. Mobo: Asus P8Z68 Deluxe
3. CPU: Intel i7 2600k
4. Memory: Corsair Vengeance LP 4 x 4GB (16GB total), 1.35v
5. GPU: My six month old Sapphire HD 6850
6. P/S: Seasonic X-560 Gold
7. Disk drives: Boot drive: not sure if I will go with Hitachi HDD or an SSD;
Data drive: two Hitachi SATA 600, 2TB, Deskstar 7K3000
8. CPU Cooler: Scythe MUGEN3
9. OS: Windows 7 Ultimate, 64-bit

Now, it's been about four years since my last build (AMD setup) and I need some clarification on the motherboard (Asus P8Z68) fan/power connectors. I've included a small jpg attachment from the User manual.

Question 1: There are two CHA_FAN connections, CHA_FAN1 and CHA_FAN2. The first one is to connect to a 4-pin (pwm) fan...understood. And the second one, what? Just use a standard 3-pin fan? Why is CHA_FAN1 +5V but CHA_FAN2 +12V?

Question 2: I'm a little unclear on what to use the PWR_FAN connector for. Also, why are there two of them?

The reason for the two questions is that I plan on installing two 120mm fans in the front intake, one 120mm intake on the bottom of the case, one 120mm exhausting on the rear, and one 140mm exhaust fan on the top. I would like to maintain a positive pressure environment in the case. So I'm just trying to figure out exactly how I will connect all these fans (yes, I will use the included Fractal Design three-fan controller).

Thanks in advance for your input.



Well-known member
Jan 16, 2012
North Carolina U.S.A
well fan a is for the cpu cooler and fan c is for the rear case fan. as far as the other i would think they would be optional fan connections. like b might be for a ram cooler setup. and d and e might go to the side panel. but to be honest i never use the mobo fan pins just the rea fan and the cpu fan connection,

to answer your other question the 4 pin on the mobo are so the fans dont run at full all the time so windows and your bios regulates how fast they spin and only run as fast as needed to cooler your cpu,
second question you asked i wouldnt use them lol. i just run straight into the fan controller you have and that way you can adjust as you see fit

hope this help a little bit


Well-known member
Jun 24, 2009
Nova Scotia
A 4 pin fan's wires are ground/12v/rpm wire/ pwm wire(not sure exactly how the rpm and pwm control work, but someone else can chime in if they know and you care) and a 3 pin is the same except it doesn't have pwm. The terminology in the motherboard manual is just unclear. In the picture the CHA FAN PWR is your 12v line for CHA_FAN1.


Well-known member
Dec 9, 2006
Calgahree, AB
PWM = Pulse Width Modulation

Fans with PWM allow speed fluctuations based off a certain circumstance which makes them generally better and quieter than non pwm fans. The issue comes in when motherboards only allow for 3 pin and not 4 pin but you can still use a 4 pin on a 3 pin you just lose the PWM .

Not sure of the +5 vs +12 tho