I recently found out from the following post that the R9 390 was now usable with AMDGPU as of kernel update 4.16.7:
I wanted to share my experience in case there are others with the R9 390 who suffered from the following bug:
For the last two years my R9 390 was basically unusable on Linux as it would always result in a blank screen when using the radeon drivers. The only time I was able to run a game with the R9 390 was when using fglrx. This was back in 2015!
The particular 390 in question is the Gigabyte G1 version. I got it to work on Ubuntu 18.04 with kernel 4.18.5. You need to upgrade your kernel and switch over to the AMDGPU driver. Below are links to perform the required steps:
Upgrade your kernel (>=4.16.7):
Because I am running Ubuntu, I used Ubuntu Kernel Upgrade utility (UKUU)
Switch over to AMDGPU:
Check the section titled “R9 390 series Poor Performance and/or Instability” and add the following boot parameters to grub: radeon.cik_support=0 amdgpu.cik_support=1 amdgpu.dpm=1 amdgpu.dc=1
*Blacklist radeon does not seem to work. I was only able to switch over to AMDGPU by performing the above.
I tested a few game such as Tomb Raider, Rise of the Tomb Raider, Shadow Tactics and the performance was excellent. Also tested some titles via steam play such as Nier and Dark Souls 3. The performance via steam play was hit or miss depending on the title. Finally my 390 is usable!