I have been googling EVGA 2080 TI fan speed issues, hi revs, etc, for a while now and finally stumbled across this thread. Incredibly helpful!
The behavior I was experiencing was perfectly described here: on hitting 80C my Fan 1 was revving to crazy loud speeds, ignoring my configured fan speed, and worse it would spin up and spin down and spin up and spin down and IT WAS MAKING ME CRAZY.
My card is getting old at this point and I saw the photos and thought "yeah, I bet that's my problem too". I popped open my card today, and sure enough the paste was jacked up. I cleaned it all off and applied fresh thermal paste. It's been running 20C cooler and ZERO fan issues now. There is a game I play that would kick the high-speed fan off within a few minutes of starting it, and I played that game today for hours with no trouble.
In other threads people have been messing with software, but the only people that got satisfaction were the ones that RMA'd their cards for new ones. Hardware issue, not software.
This seems to be some kind of hardcoded fan threshold that is poorly coded, but is mostly fine until your card starts to get hotter and hotter over time as the paste deteriorates.
All fixed now. Thanks again.