GA-P35-DS3L and its Sys_Fan2 header REPHRASED question


Oct 14, 2007
Apparently I wasn't clear enough, and I got insulted quickly. Don't jump to conclusions and let me rephrase then. Especially that English is my 2nd language.

I know about the CPU FAN thing so, to start from the beginning :

I had an old system fan which I wanted to change...

I first had an E6750 with the stock Intel Fan plugged into the CPU_FAN header, using smart fan to PWM in bios. Worked flawlessly.

Now to replace the old system (case) fan, I bought that PWM Artic Cooler 12PWM. I had tried to do some research about the SYS-FAN2 4-pin header, but as there was limited litterature, I took a chance and hoped that a PWM fan would work and regulate itself according to system temperature (not cpu) when plugged to SYSFAN2, even though in BIOS there is no option for System Smart Fan Control.

But when plugged to SYS-FAN2 header, the PWM-type fan does not spin at all.

THEN, and only then, I used the Arctic Cooler PWM sharing technology (it's a sort of splitter) and now BOTH the CPU and CASE fans are plugged together in the CPU_FAN header and BOTH fans regulate themselves based on the CPU temperature. Temperatures are fine and within normal ranges for CPU and system. Everything works, but I only wonder the following :

What is the purpose of having a 4-pin header SYS_FAN2 if you can't use the PWM 4-pin fans???? I noticed that in manuals for other motherboards, there is such a thing that specifies PWM as smart fan control for a system (case) fan, which we do not have in the GA-P35-DS3L bios.

Hope I was clearer and thanks for your kind answers.