RainStrykeYeah, you are stuck with it. One thing though... Are you sure it's the GPU? I had a 750w G5 PSU. The first one was loud and noticeable, the RMA unit... O M G the coil whine sounded like one of those . Luckily I got my money back and never looked back. Not a fan of the G5 line-up. They used FSP for that line-up and it's definitely lacking compared to their Superflower units.
JayManBWhat games and how high are your framerates? My experience is that a lot of GPUs coil whine at over 150 FPS or so. Especially in menus where the framerate can go into the hundreds. I usually limit my games to below the refresh rate of my monitor which is 144Hz. I have the XC3 Ultra and its actually quieter than my 1080TI it replaced as far as coil whine is concerned. I hope you get it figured out sucks when you get a new part and have problems with it.