Help with chassis/power fan connectors on motherboard

Gary Seven

Junior Member
Dec 17, 2011
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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 below a link from the User manual.
http://flic.kr/p/bnqzHU

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.
 
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coffeejunkee

Golden Member
Jul 31, 2010
1,153
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1. Not completely sure what the 5V is for, but it's not for powering the fan. Cha fan pwr pin takes care of that and I'm sure it's 12V. So cha_fan1 cannot control pwm fans by pwm signal but would be able to control them by voltage (just like regular 3-pin fan). Also, both cha fan headers are controlled by the same circuit so no individual control.

2. Pwr_fan headers are supposed to be used for reading out psu fan rpm. Personally I've never seen a psu with this feature but I heard some older Enermax have it. 2 pwr_fan headers would be for dual psu systems I suppose (which would be extremely rare). I don't think these fan headers offer any form of control (unless Asus changed this compared to previous models).

CPU fan header can only control pwm fans btw. Non-pwm fans run at 100%.
 
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coffeejunkee

Golden Member
Jul 31, 2010
1,153
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I don't think 2 fans on 1 header will cause any problems. Every slightly decent mobo gives more than enough power to the fan headers. I'm using such a splitter myself for a long time now and no trouble at all. 195 positive user reviews must say something as well.

Putting 5 fans on 1 header might be too much though.