CNPS9500 LED/AT?

[soydios]

CNPS9500-LED http://www.zalman.co.kr/eng/product/view.asp?idx=165&code=009

CNPS9500-AT http://www.zalman.co.kr/eng/product/view.asp?idx=193&code=009

what's the difference? the CNPS9500-LED comes with mounting hardware for 478/775/754/939/940, and the CNPS9500-AT comes with mounting hardware for LGA775 only. Is the fan connector the only difference? If so, why 4-pin over 3-pin?

 

[RallyMaster]

The fan is also the other...well...obvious difference. The LED has blueness while the AT is completely black.

 

[Operandi]

The AT uses a 4-pin PWM controlled fan that is controlled by the motherboard. The 4th pin is dedicated to PWM control and offers a greater range of control then a traditional 3-pin fan controlled by PWM.

As far as I know only LGA775 and AM2 motherboards have 4-pin CPU fan headers.