Since I have owned my 6800xt, I have noticed coil whine. I don't know if it is getting louder, or I am just more sensitive to it, but sounds like a bunch of bees in my case. Is this dangerous and should I pursue a RMA, or more just annoying?
Pretty normal in most cases, have a search online and will get lots of feedback everywhere.
My RoG Strix RX480 did some but I learned how to mitigate it. VSYNC or FreeSync can help with coil whine in some games instead of VSYNC Off.
Limiting the Fps a bit above the refresh rate on Adrenalin can help too.
The only bad Coil Whine is on the PSU, if it does then its bad. Learned the hard way.
Just my 2cents