I just installed an onl amd 6790 video card.
It is comparable to the broken gtx 580 it replaced. But when playing dota2 the framerate was less than half.
I then loaded up Windows 10 and tried dota2 on the 6970 there. The framerate was triple! I was getting framerates around 90 fps, where on linux I was getting around 30.
Surely something is misconfigured, as the os could not account for such a massive drop.
I did not install the amd proprietary drives on Linux since they said "unmet dependencies", so I just used the open source ones that were already packaged with 20.04. I have read the open source gaming performance is equivalent to proprietary anyways.
So what gives? How can I get somewhat comparable dota2 framerate on Linux as I do on Windows 10?