My admittedly limited experience with these cards has taught me this: Vega is SUPER SENSITIVE to power supplies.I Think I know why I got such a good deal on this Vega 56.. what I thought might be a squirrely fan motor might be coil whine? Are these known for coil whine issues? I wear headphones when I game at night so it's not an issue.. but it's the first time I've encountered an issue like this.
Overdriven tool works great btw
Make sure that you are using different PCIe plugs from the power supply instead of using two plugs on the same cable, if you are doing that. Avoid using Molex-to-PCIe power adapters. Make sure your power supply is no less than 750W (again, in my limited experience), and you might STILL need to replace the power supply with a newer (reputable) one if it is more than a year or two old.
My Vega 64 whined like a bitch on my older Antec TruePower 850W. It was truly obnoxiously loud any time a game started up and nothing I did could get that to stop, so I replaced the power supply with another one I happened to have handy. It is almost entirely gone now using this much newer Antec TruePower 750W power supply. If I get into an older title that really ramps up the FPS, I can still hear it faintly, but like I said, mostly gone now. If that were still bothersome to me, I could actually enable the Frame Rate Limiter in the Radeon drivers to eliminate it entirely.