BAH.. looks like the forum doesn't allow links?  ok...
 
I have a FTW3 1080ti card, and Precision XOC running, but the GPU fan is not using the custom fan curve. The Power and Memory fans DO work, and change speed as I change the curves and hit OK, but the GPU fan will not respond. I can manually slide the speed and hit apply, and the fan responds and changes speed, but not to temp, only the position of the slider. As the card temp goes up or down, only the power and mem fans change speed. The rpm readout (and sound) of the GPU fan seems correct to what the slider position is. You can see in the attached pic the GPU speed should be similar to the others, but it is stuck at 600 rpm (I tabbed out of a game and saw the GPU temp was 81, and the GPU fan speed was only 600 rpm). 
 
It does seem to work sometimes, but just as often not. Also, XOC seems pretty flaky and crashes more than I feel it should. But my main issue is the lack of curve control for the GPU. What could be the issue? This has been a problem with the last version I was using (2 or 3 versions back), and I installed the other day, hoping the issue would be fixed, but sadly it is not. System is running Windows 10 pro 64, Asus Maximus Hero VIII motherboard, FTW3 1080ti (stock clocks), and XOC 6.1.15.
 
Ideas? Thanks
-David

 

Valtrius Malleus
It looks like you need to click the little fan button above the slider so it will adjust to the temps automatically and use the fan curve instead of the slider. It will change colour like the other two fan icons when in auto mode.

I agree.  It does look like the other two fans are active (auto), but not the 1st one.

whaleboy_abc
...click the little fan button above the slider...
 
Jeez... had no idea those were buttons. The color shift is so subtle to me that I can barely tell the difference between off and on. I wish they had a frame/border like the bigger master fan button so I would know that they are buttons. Consistency in the UI would be a good thing. I don't have time to test the card, but that looks to be the issue. How I am randomly turning that on and off, I don't know, but at least I now know what to look for if it stops working again.
 
Thanks
 
-David

It's alright. They say that those who ask questions know more than those who don't ;) Now you know!
 
Adjusting the slider directly will switch off the fan curve but if you didn't touch it before it went manual then I have no idea. One of the many mysteries of PrecisionX OC.
 
FYI. Clicking the chain icons below the sliders will cause the other fans to use the same speed as the GPU fan, regardless of their temps or fan curve.

Absolutely drop those curves. 1080ti is good to run in the high 70's/low 80's, so you have plenty of room to lower them.