I'm using Kubuntu 18.04. I switched my AMD HD 7950 with a RX 580, and I can't boot regularly with it. After the Grub boot menu, I get a glitched screen (mostly plain black, with a few colored lines at the bottom). Sometimes (but not systematically), the GPU fans launch for 2 secs at this step. Then the screen become plain black and nothing happen, I cannot enter a tty session with Ctrl+Alt+F(x). Only reset. If I boot in recovery mode, I can enter the graphic session in low res mode. I tried enabling the proprietary drivers (amdgpu-pro), but to no avail (installation went well but it did not solve the above mentioned symptoms). I was expecting it to work out of the box with the open source AMD drivers. The card itself is in working condition, I can launch my games in hi res under Windows.