connect CoolerMaster Hyper TX3's 4-pin to 3-pin connector

[ramik]

With summer, I changed the cooler of my system (Signature) from the stock AMD that came with the Opteron 165 processor (a Foxxcon 4 heatpipes, copper base with aluminium fins), and got myself a CoolerMaster Hyper TX 3, one of the few that i found that still support 939 sockets.

 

But there is one problem (well, 2 in my case):

1- This hsf has a 4-pin connector, and the motherboard has only 3 pin connectors, so 1 pin should be unused, the guides on the 4pin seems to connect the correct 3 pins from the 4.

2- the DFI UT nf4-UltraD's 3pin connector for the CPU fan is near a capacitor, and the 4-pin of the cooler master can't be inserted in the CPU fan connector.

 

Anyway to get the system working i installed the CPU fan connector to the 'FAN 2' connector (the PWM fan) and everything seems to work, playing the the bios options of the PWM temp i reached a good point where the motherboard control the cpu fan as if it is the case fan, varying from 900 rpm to 2800, good enough for now.

 

if i want to mode the 4 pin connector, can i simply cut the 4th unused pin? what is it for? the fan already reports speed and get its speed controlled. so what is it for?

 

Anyway, i am already satisfied with this Hyper TX3, temperature dropped by nearly 10 degrees on full load, with stock fan CPU temp used to reach 68 °C, since yesterday the max i saw was 56, in addition to be much quieter...

[airman]

If it's working fine right now plugged into FAN2, there is no need to cut the pin If you're itching to use the CPU fan header, you can take off the 4th pin. See here:

 

http://www.allpinouts.org/index.php/Motherboard_%28CPU%29_4_Pin_Fan

[ramik]

It's working, but i'd like to have it say CPU fan

seeing the pinout, the unused pin is the CONTROL, so if it's not connected how is the speed varying? mobo is controlling by changing voltage?

 

update:

better to connect to cpu header, as this morning the case was cold and the fan went off for few seconds !!!