Unreal Engine 5 has 2GB VRAM with AMD open-source drivers

[keet]

Squad recently released version 9, which uses Unreal Engine 5. I noticed very low framerates when running the game; it was basically unplayable, maybe 2 to 5 FPS.

Setting the command line to use the proprietary driver restored decent performance, though not as good as before:

VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/amd_pro_icd64.json %command%

However, I read that the open-source drivers generally work better and prefer to use them for philosophical reasons.

I noticed that the Steam overlay said that the game is using only 2GB of VRAM when I use the open-source drivers for this game, but uses my video card's full 20GB using the proprietary ones. This seems directly related, as it also shows that the game is trying to use far more than that, even on just the loading screen.

I downloaded a random free Steam game that uses Unreal Engine 5, The First Descendent, and it does the same thing, which leads me to think that this affects all UE5 games.

Does anyone have any ideas? My video card is a 7900XT.

[ritzmax72]

I fire up dead by daylight once in a while and it ran as smooth as before.
I am not sure if they are on UE5 or UE4.
About Squad, from my youtube channel I can see I played it
back in Nov 2024. I am not sure if it was UE5 that time or not.
This whole UE5 situation gives me anxiety because UE4 was so good
and most games ran so well on Linux (10-12 fps lower than Windows on average).
I almost finish Black Myth Wukong on Linux and I guess it is on UE5. Surprisingly
BMW was excellent. I used open source amd drivers to fix the frame rates. Before that
I was using proprietary. I guess the open source driver is called xf86-video-amdgpu.
Also had to tweek some files. You can see my BMW performance here.
https://www.youtube.com/watch?v=vQcQer3dJtc

[ritzmax72]

I noticed that the Steam overlay said that the game is using only 2GB of VRAM when I use the open-source drivers for this game

Yes. I also had similar issue. You have to make changes to some files and also do some changes from within the game.
I guess my thread would be up here somewhere. Try searching forums with my username. I did this one year ago. This is fixable issue.

[ritzmax72]

More help for you.
1. https://forums.gentoo.org/viewtopic-t-1 ... ight-.html
2. https://forums.gentoo.org/viewtopic-t-1 ... ight-.html

I gave these two threads a glace (both opened by me).
Basically you should use RADV (aka mesa) drivers (amdgpu as USE flag).
This installs both opengl/vulkan drivers. This is open source but it is non-AMD
or unofficial (Khronos group) made drivers.

The alternative to mesa's vulkan is AMDVLK.

The alternative to open source driver is closed-source amgpu-pro. This
installs both vulkan and opengl drivers.


It is said you can have all of the above 3 installed (mesa, amdvlk, amdgpu-pro)
posted on thread #1 and switch between them. The person replying to me wrote a script if you are interested.
Personally, I only have mesa installed which covers both opengl and vulkan and BMW/EldenRing/NightReign/Witcher3/Squad have
run excellent in 2024. BMW being on UE5. You have to make sure you have only one variant of vulkan drivers (mesa/amdvlk/amdgpu)
as wine translate DX11/DX12 to vulkan for modern games. You can try amdvlk and amdgpu to test the performance.