It looks like there is a trivial, yet crippling issue with AMD's new Radon VII preventing it from living up to the potential of the hardware: the base of the stock cooler is concave, which prevents it from receiving heat from the GPU efficiently. The solution: sand it down a bit to make it flat (and add washers to get the proper mounting pressure). Result: peak junction temperature falls by 40°C, throttling is no longer an issue, the card becomes overclockable! At least judging by this Reddit post. EDIT: Looks convex actually, judging by the first photo after he starts sanding. Not flat either way.