Hello,
I keep having this problem pop up about every couple of months where my gpu will start running its fans at high speeds making it quite loud. Looking in Radeon settings it shows the current fan speed at 0, but on the chart it will have a spike reporting 3600+ rpm. Task manager shows that nothing is using the gpu, so I don't suspect malware. It will also go back to normal fan speeds after a while, but I'm not sure what causes it to do so. Any help would be much appreciated as I haven't found anything relevant with google searches.
For anyone wondering my 480 is the Asus ROG Strix and I haven't done any overclocking to it.
EDIT: I should add, even though radeon settings reports 0rpm the fans are still running at what sounds like max speed.