Same errant results in F28 & F29.
inxi -Gxx Graphics: Device-1: Advanced Micro Devices [AMD/ATI] Oland [Radeon HD 8570 / R7 240/340 OEM] driver: amdgpu v: kernel bus ID: 04:00.0 chip ID: 1002:6611 Display: server: Fedora Project X.org 1.19.6 driver: amdgpu unloaded: fbdev,modesetting,vesa alternate: ati compositor: kwin_x11 resolution: 2560x1080~60Hz, 1920x1200~60Hz OpenGL: renderer: AMD Radeon HD 8500 Series (OLAND / DRM 3.27.0 / 4.19.2-200.fc28.x86_64 LLVM 6.0.1) v: 4.5 Mesa 18.0.5 compat-v: 3.0 direct render: Yes
xorg.conf file that produces expected results on openSUSE Tumbleweed with 4.19 kernel and 1.20.3 server: http://fm.no-ip.com/Tmp/Linux/Xorg/Cfg/xorg.conf-4480x1200-amdgpu
Log from F29 using same xorg.conf resulting in X ignoring all three options: http://fm.no-ip.com/Tmp/Linux/Xorg/Cfg/bad/xorg.0.log-f29-4480x1200-amdgpu-r...
Is this expected? Am I missing something about global X configuration while using KDE that's different in current Fedora from current TW?