I have some artefacts / refresh rate issue on my bios only with my 290X (Fury and 7950 ok on this computer).
There is a line on the left which corresponds to a repeat of pixels in the center of the monitor. Also artefacts on the text (repeat).
No issue on windows. Same issue when booting to a linux system.
When i'm showing my screen OSD i have 139Hz and not 144Hz...
Any idea? I've tried another DP cable...