Thanks for watching the DOOM Video 2 above to see the low FPS with Vulkan API in DOOM on Fedora 28 problem I described.
I tried alt+tab out and back into DOOM before and it does not improve the FPS. I just reran DOOM to check again. alt+tab to another application or ald+enter to go from windowed to full screen makes no difference to the FPS either.
I think the reason I see poor Vulkan Performance in DOOM 2016 on Fedora 28 is as follows.
The now renamed Radeon™ Software for Linux® which contains the AMDGPU All-Open and AMDGPU-Pro Driver is not available for Fedora 28. I think this is also the case for a number of other Linux Distributions.
More information can be found here:
The only driver officially available for Fedora 28 is the Mesa Driver.
It does look like there is a project on Github which attempted to provide the AMDGPU All-Open and AMDGPU-Pro Driver for an earlier version of Fedora. I will attempt to contact the developer about that.
I see very good Vulkan Performance on DOOM on UBUNTU 16.04 LTS with the “Radeon™ Software for Linux®” AMDGPU-PRO driver installed.
I demonstrated that last week in this video, which I repeat here only for your convenience:
I immediately tested Steam Play Beta when I read the announcement about it on DOOM 2016 on my Ubuntu 16.04 LTS installation which I was running at the time.
This, along with your feedback points me to the initial conclusion that the Mesa Drivers have poor Vulkan Performance.
I think the best place for me to continue to investigate this issue is to ask on the Fedora and AMD Community Forums.
If I find out any more information about this I will report back here on this Forum.
Thank you again for taking the time to reply to my question.
I really appreciate your help and feedback.