How to use FSR4 on RDNA3 cards for Darktide on Linux

Warhammer 40,000: Darktide Player Guides
1

This is not a gameplay guide but rather a quick guide on how to improve both visuals and performance using FSR4 on RDNA3 GPUs by AMD.

FSR3 is already in the game but one of the main complaints users have is the shimmering effect it causes in the image.

FSR4 removes the shimmering effect by improving the image quality while still providing performance gains over other anti-aliasing methods.

However AMD only made FSR4 available on RDNA4 GPUs. This meant users on the older RDNA3 GPUs could not enjoy the benefits of FSR4.

Fortunately a few developers found that FSR4 can be enabled on RDNA3 GPUs, just not officially.

In order to enable FSR4 on your RDNA3 GPU, you will need to install OptiScaler to your Darktide game.

Install Guide for Linux users

I play on Ubuntu 24.04 with an RX 7700 XT GPU at 3440x1440p. My performance for some settings are:

TAA - 30-40fps
FSR3 Quality - 60-70fps
FSR3 Quality + Frame Gen - 100-110fps

FSR4 Ultra Performance - 60-70fps
FSR4 Performance - 50-60fps
FSR4 Balanced - 50-60fps
FSR4 Quality - 40-50fps
FSR4 Quality + Frame Gen - 70-80fps

Installation Steps

1. Download and install OptiScaler

  1. Search for OptiScaler on Google and find its official GitHub page
  2. Navigate to releases and download the latest zip file
  3. Extract the zip file and put the contents into the Darktide binaries folder (found in base game directory). Confirm any overwrites.
  4. Rename the OptiScaler.dll file to dxgi.dll
  5. Open the OptiScaler.ini file and set Fsr4Update=true and ShortcutKey=0x24
  6. Set the launch commands for Darktide in Steam:
PROTON_FSR4_UPGRADE=1 DXIL_SPIRV_CONFIG=wmma_rdna3_workaround Fsr4Update=true WINEDLLOVERRIDES=dxgi=n,b %command%

2. Install compatible Proton versions

  1. Search for ProtonPlus and find the official GitHub page
  2. Scroll down and install via the FlutHub link
  3. Use it to download and install GE-Proton10-27
  4. Configure Darktide in Steam to use GE-Proton10-27

3. Install mesa 25.2.0 or newer

  1. Open terminal and type glxinfo | grep "Mesa" (might need to first run sudo apt install mesa-utils in order to use the command)
  2. If it reports you have mesa 25.2.0 or newer, skip to next section
  3. Otherwise run the following to install the latest stable release of mesa:
sudo add-apt-repository ppa:kisak/kisak-mesa
sudo apt update
sudo apt upgrade
  1. Restart PC

4. Configure OptiScaler

  1. Launch Darktide and set it to use DLSS first (just for now, otherwise OptiScaler may crash your game)
  2. Press the Home key to open OptiScaler and under the upscalers section select FSR 3.X/4 and click the change upscaler button
  3. Under the FFX Settings section the dropdown should default to FSR 4.0.2
  4. Now go back into your game settings and turn DLSS off and FSR3 on
  5. Open the OptiScaler menu again and under the upscalers section it should read FSR 4.0.2 | Input: FFX-DX12 if everything is working correctly
  6. Choose the model number (under the FFX Settings section) that corresponds with the FSR3 preset you chose in the game settings. Leave on ‘Default’ if you want it to do this for you automatically.
  7. Optionally enable frame-gen in the game settings.

Enjoy!

That should it be it.
Enjoy!

2 Likes
2

Thank you for your guide.

I own a RTX 5080 and I have been pushed by Microshit to Linux (they destroyed my OS without even a warning or a word)

I use Fedora 43 with KDE. So far, I am totally impressed by the OS. I think that I will remove Wincrap soon.
My tests with steam is 90% games work. I have 3 that need investigations… 2 of them I have solutions, I just need to read and apply the how to fix them.
The last is… Darktide. It launched, but I need to succeed to make Ray tracing and frame generation to work.
But at least, you confirm we can play…

Anyways, or I fix the situation, or I uninstall Darktide. No way I return under wincrap. If I cannot make Darktide working, well I will push the uninstall button.
Macroshit has really pushed too far with the 25H2… and what they plan after that is even worse.
And to be honest, I am really surprised by how Linux is really better. Valve did a great job, and MS is still 10 years late behind Linux in term of interface and customization for the OS.