946gz7ma-8krs2h fan setup

Hello, i bough a 946gz7ma-8krs2h mobo bundle a while back and decided to set it up as a server.

My issue is that the fans are constantly running at full speed ( cpu 2400rpm, case 1400rpm )

I couldnt find anything in the manual regarding the bios settings for this, i have these options:

PWM Start Temp
Start PWM Value
Slope PWM Value
Delta Temp

Any ideas what each of them does?

I have also enabled ACPI in the bios (before i setup windows, windows shows support in the device manager) and neither fanspeed or the mobo utility (fox one) has any effect on the fans ( they can detect the speed and temps ok, but when i change the speed the rpm doesnt change)

This is pretty loud and is starting to drive me crazy

any help would be greatly apreciated

thanks,
--Dan