I have a Gigabyte RX 550 2GB DDR5 , I use X-plane a flight simulator which is an Opengl based game.
Have terrible performance in opengl for both under Windows 10 and Linux. Though i am a bit bottle necked due to CPU / RAM , the new upgrade is planned for next year , hence i tried the other flight simulators which are DX11 - DCS World / il2 and both these perform like 40-50 fps which is actually good.
X-plane under windows will give me not more than 15-18 fps and under linux it's worst where it actually chokes the system and with similar fps. Today morning i decided to upgrade to Adrelaine 18.10 from 18.5 and wow i was getting 9 fps.
Using Linux 18.4 AMDGPU-Pro and on windows 10 - 18.10 (will be going back to 18.5).
Hence for linux i had to use the open source Mesa / Gallium which give me around 10-15 fps more which is quite good, But X-plane developers said they don't support open source Mesa / Gallium and i am stuck with this problem.
X-plane will be going with Vulkan starting early next year .
I hope the technical staff of the GPU drivers development team take into consideration as what the problem is with Opengl in the drivers.
The other test i carried out was using American Truck Simulator which is again availlable for Directx and Opengl and supports both windows / Linux. The same issue if tried under AMD Adrenlain under windows using Opengl (8-10 fps less) and under Mesa (linux ) better performance.
Need anymore info then please let me.
My config :
AMD X4 810
8 GB DDR3 1333Mhz
Gigabyte RX 550 2GB DDR5
Windows 10 / Lubuntu 18.04