4 pin cpu fan pugged into a 3 pin mobo header

openhead

Distinguished
Jul 31, 2011
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I am new to this stuff.. I have a MSI 870-G45 with an AMD Phenom II x4 965 cpu and stock 4 pin cpu fan. I recently transfered these contents from an old case to a new NZXT H2 case.
Upon initial startup, the computer stayed on for about a minute then shut off. Upon investigation, I found that the cpu fan was not turning on.
I read somewhere that you can test the fan by plugging it into a 3 pin header on the mobo. Upon doing so, I found out that the fan still works, leading me to believe that its the mobo 4 pin header that is malfuntioning.

My question is: Is it safe to run the computer with the 4 pin cpu fan plugged into a 3 pin mobo header? Or will this result in the computer blowing up in my face, leaving me disfigured and generally ugly (more so than now) for the rest of my life?
 

sykozis

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Dec 17, 2008
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3pin fan headers provide for power, ground and rpm signal. 4pin fan headers provide for power, ground, rpm and voltage control (PWM functionality). The only difference between using a 3-pin and 4-pin is that the bios won't be able to control the fan speed. It won't have any negative effects drastic enough to directly effect your daily life...lol.