Quote Originally Posted by vipertwo View Post
Thanks gtj and clark.

gtj did you intend the scaling to be set up in sensors.conf ? ( actually sensors3.conf -- I'm using sensors version 3.0.1 with libsensors version 3.0.1). If so then we would just need to know how to set it correctly.
I haven't touched it so far.

I have now attached fans to the CPU fan header, the "Rear Fan" header and the "Rear Fan 2" header (called Aux in BIOS). Can't get at the front fan header without dismantling the computer so will leave it for now.

The CPU fan shows up in the sensors display as fan1, RearFan2/Aux shows up as fan 2, but the Rear Fan RPM is missing.

The BIOS also shows zero RPM for the rear fan but it's definitely turning. Is this a known problem?

By the way all speeds and voltages are at default - no overclocking or overvolting.
There should be no scaling in sensors.conf. The driver outputs the correct values for voltage, temp and rpm directly. I'll look at the 3.0.1 version and see what it's doing but now that I think about it, they look actually correct for the Bonetrail and a QX9650, especially when idle. I may have been thinking about the XBX2.

Are you sure you have the rear fan plugged into the correct header on the MB? There are 2 in that general vicinity. The one behind the audio stack is the MCH fan and isn't monitored or controlled. The one behind the mounting hole next to the audio stack is the rear fan header.