system fans vs. power fan headers?

[Beau]

What's the difference? My board has:
3 pin (SYS_FAN1)
+
4 pin (SYS_FAN2)
+
 3 pin power fan header (PWR_FAN).

I'd also like to turn down the RPMs on my 120mm front case fan to reduce noise soemtimes. The Green utility thingy seemed to want to cut back on the CPU while reducing the fans and I didn't like that. Non-Gigabyte "SpeedFan" software didn't list my board.

Thanks.

[Dark Mantis]

Hi

The main difference between the 3 and 4 pin fan headers is that the 4 pin are  speed controllable and can be read out via the BIOS if the correct fan is fitted.

Sysfan2 is only half the speed of the other fans.

[Beau]

Thank you.