Hi! I'm still pretty new to linux, but I would consider myself a windows "Power User". I would always OC my GPU in windows using WattMan, AfterBurner etc., and while I got good results, it was never any thing like this:
(Left is stock w/o CoreCtrl daemon running, right is OC pictured below)
https://ibb.co/gvNsTmY (only one image for new users; only been lurking until now)
Does MESA do some sort of underclocking in OpenGL that I don't know about? Is this a power issue. I'm honestly lost here. If ya'll need anymore info I'd be happy to provide it.