I had a running xubuntu 15.04 (3.19 kernel) desktop with 16GB RAM on an ASUS A88XM-PLUS mainboard with an AMD Radeon R9 390 GPU which used the fglrx-update drivers. The system was installed with an AMD HD7770 GPU, later I upgraded the graphic card without much of a hassle to get better game performance. The only drawback was that the new card couldn't use the same DVI-to-VGA adapter I needed for my old Sony Multiscan 420GS CRT monitor, so I got a DisplayPort-to-VGA adapter. Otherwise I use a Samsung PS63A756T HD TV for video and gaming.
I tried upgrading the system once or twice but always without success as the R9 390 card was not well supported driver-wise on newer ubuntu versions (without fglrx). Now with the arrival of ubuntu 16.04.2 with the new 4.8 kernel and the AMDGPU-PRO drivers supposedly supporting the R9 390 I upgraded again, ruining my working system in the progress. Now after two very stressful days I have accomplished the following:
- I did fresh install of xubuntu 16.04.2 from DVD with the old HD7770 GPU in the pc.
- I installed the AMDGPU-PRO 16.60-379184 drivers from http://support.amd.com/en-us/kb-articles/Pages/AMDGPU-PRO-Install.aspx
I noticed a very curious thing: Still running the HD7770 GPU I could not get sound on the HDMI-connected TV as all HDMI options in the Volume Control configuration were marked as "unplugged". Then I switched the graphic card to the Radeon R9 390. This resulted in:
- HDMI sound was active again.
- The VGA CRT monitor was no longer receiving any signal from the GPU (via the DP-VGA adapter). So it is currently impossible to use it at all.
- Massive screen tearing happens all the time on the Samsung TV. Regardless of playing a game, watching a video or just using the desktop, this is very noticable. While playtesting Tomb Raider Underworld (in Wine, obviously) the display completely went black after a few minutes and didn't return (system froze).
So now I am at a loss. Can this flickering/screen-tearing issue be solved? I cannot find anything like the old Catalyst Control Center to activate tearfree display or vsync. And why is the DisplayPort-VGA adapter or the DisplayPort on the graphic card not working? I pretty much need the CRT and know both the adapter and the monitor work fine.
(One last weird thing: I switched the graphic card again to the old HD7770 (to have a working monitor again) and the display settings no longer recognized the CRT as "Sony 18''" with many supported resolutions (up to 1600×1200) but only as "Digital display" with a max 1024×768 resolution.)