Nice easy one to start me off - I hope
![Smiley :)](http://forum.giga-byte.co.uk/Smileys/default/smiley.gif)
It's clear from the manual that the the fan connected to the CPU fan header has smart speed control using either voltage or PWM - depending on how BIOS is configured. I've tested this with EasyTune6 and it works exactly as described. If I disable Smart Fan the CPU spins up to maximum and I can tune the speed as I desire using the advanced option.
However, the same behaviour is not seen on the fan connected to the system fan header. Regardless of the settings in EasyTune the system fan stays at it's lowest RPM.
I have tried this with three fans: (i) 3-pin Silvetsone Globe 120mm (ii) 4-pin Akasa Apache 120mm, and the 4-pin Slipstream fan on the Scythe "Big Shuriken" CPU cooler. The Silverstone and Slipstream spin up to their lowest RPM and the Akasa doesn't spin up at all - it 'twitches' suggesting that voltage isn't high enough to get it going.
So, a couple of questions:
(i) Is voltage speed control supported on the system fan header? (I'm dismissing PWM since pin 4 seems to be unused)
(ii) If it is supported, are there any special requirements for this fan?
Having tried three different fans already and seeing the same result I can only conclude that either voltage speed control isn't supported or I have a broken board. If it's not supported I'm surprised since the manual and specifications suggest that it is.
Other things to note:
(i) All fans known good and speed control tested on another motherboard.
(ii) 440W Seasonic PSU, machines uses at most 70w during boot and 45w when idling.
(iii) Have cleared the CMOS and reinstalled the BIOS to F9, and downgraded to F1, then back again.
(iv) This is a rev 01 GA-H57M-USB3
(v) This is a new build.
So, in summary: not supported or bust?
Cheers.