Hello, I have had my 1080Ti FTW3 for a while now and there seems to be a minor issue that has me a little concerned. I took both side panels off my case to do some semi-open bed overclock testing. Afterwards I just left them off for the sake of thermals. Because of this I can fully see the outermost fan while I'm using the computer. I have noticed that from time to time the fan will just pause for a few seconds before resuming normal operations. I'm not sure if this is happening to the other fans as it does not seem to be predictable. If it's any help, the fans seem to have a slight "chugging" behavior with fan noise, maybe one rev per second and fairly faint. I have a linear fan graph on all three fans using Precision X1 and all graphics drivers are up to date. Any input is appreciated, thank you.

I've only noticed the pausing at idle speeds, as of right now the GPU temp is 22C and it has done it a few times recently, the slight revving can happen at 100% use temps, which is usually ~55C

Any ideas on how to diagnose it? 

Good troubleshooting on your part. If this situation changes please let us know. 

Did X1 auto update the version ?

Update: After doing the reboot and the plateaus I reset the settings on Precision and tried that. On the upside, it has gotten rid of the revving, on the not so good the idle temp pausing is still occurring, rarely and for only about 1-3 seconds. It's not very often but it does occur. Since it's not happening at high temps and not detrimental to performance, I suppose it's an "oh well". I just hope it's not symptomatic of something more serious

Re-Update x2: sorry for the frequent updates, I'm posting as I learn things. So it is happening to the other 2 fans. X1 will accurately show the rpm and when it shows 0 the fan will indeed be stopped. My lowest idle speed is 40% and at idle the fans will show the 40% but will drop to 0 for extended times (5-10 seconds). 

The all fans wont seem to operate without precision 

I noticed the fan i can immediately see wont spin until i pull up x1 so I haven't dared to load test it. but with operational fans my temps don't go over 60 

Would HWMonitor be ok to use instead?

No fans will spin without X1, but I did some digging in programs and when X16 upgraded to X1 it didn't delete the previous version. I deleted the old X16 and everything seems to be working as intended, was likely conflicting with X1, will continue monitoring.