If you’re playing Clair Obscur: Expedition 33 on your Steam Deck, you’ve probably noticed it doesn’t run well by default. With performance dropping as low as 18–24 FPS in some areas, the experience can feel sluggish and even unplayable in combat.
Thankfully, there’s a community-made optimization mod specifically tailored for the Steam Deck. It dramatically boosts frame rates – without compromising visuals – so you can enjoy smoother gameplay that feels responsive and looks great.
Ultimate Guide to Optimizing Clair Obscur: Expedition 33 for Steam Deck – High FPS & Stunning Visuals
This step-by-step guide will walk you through downloading, installing, and configuring the mod for optimal performance on the Steam Deck.
Why Use This Optimization Mod?
On launch, the game’s performance on Steam Deck varies from mediocre to poor. Common issues include:
- Inconsistent FPS, especially in combat
- Input lag that makes dodging and attacking difficult
- Overworld frame rates dropping below 20 FPS
This mod was built from the ground up for Steam Deck users running SteamOS with Proton, Vulkan, and DirectX12. It boosts performance by carefully adjusting both visible settings and engine-level configurations.
Key Benefits:
- 45 FPS in combat
- 48–55 FPS in maps and dungeons
- 30 FPS in the overworld (previously ~20 FPS)
- Enhanced visuals without a big FPS hit
- Seamless playability with minimal visual downgrades
What the Mod Actually Does
This isn’t just a “low settings” preset—it’s a deep optimization mod that includes:
- Tweaked almost every visual setting to preserve visual quality while increasing performance
- Adjusted engine parameters related to garbage collection, shaders, multithreading, and UE5-specific systems
- Built specifically for SteamOS on the Steam Deck using Proton with Vulkan and DX12
You’ll enjoy higher frame rates without noticeable visual degradation.
Step-by-Step Installation Guide
Step 1: Download the Mod
Download version V5 of the mod from Nexus Mods here:
https://www.nexusmods.com/clairobscurexpedition33/mods/25?tab=files
Once downloaded, extract the ZIP file to reveal two files:
GameUserSettings.ini
Engine.ini
Step 2: Replace Game Config Files
Navigate to the following folder on your Steam Deck:
/home/deck/.local/share/Steam/steamapps/compatdata/1903340/pfx/drive_c/users/steamuser/AppData/Local/Sandfall/Saved/Config/Windows/
To get there:
- Open the file manager (Dolphin)
- Paste the path above into the address bar and press Enter
- Or manually navigate starting from your Home folder
Inside that folder, you’ll see an existing file called GameUserSettings.ini. Delete it.
Now, copy both GameUserSettings.ini and Engine.ini from the mod’s ZIP file into this folder.
Step 3: Make the Files Read-Only
To prevent the game from overwriting your optimized settings, you’ll need to make both files read-only. You can do this in one of the following three ways:
Option A: Through the File Manager
- Right-click on the “Windows” folder (the one you just added the files to)
- Choose “Properties” > “Permissions”
- Set it to “Can Only View Content”
Option B: File-by-File
- Right-click each file (Engine.ini and GameUserSettings.ini)
- Go to “Properties” > “Permissions”
- Set to “Can Only View”
Option C: Recommended via Terminal
- Open the folder containing the files
- Right-click and select “Open Terminal Here”
- In the terminal, type the following two commands:
chmod 444 Engine.inichmod 444 GameUserSettings.ini
This locks the files from being changed.
Step 4: Set Steam Launch Options
To finish the setup, you need to add a command in the game’s launch options.
In Steam:
- Go to your game library
- Right-click on Clair Obscur: Expedition 33 (or use the gear icon if in Gaming Mode)
- Select “Properties”
- In the “General” tab, find the box labeled “Launch Options”
- Paste the following into the box:
SteamDeck=0 RADV_PERFTEST=aco,gpl %command%
This tells the game to use more aggressive GPU optimization flags and ensures the settings work as intended.
Optional but Strongly Recommended: Upgrade XeSS
Intel’s Xe Super Sampling (XeSS) can further improve performance and image quality on the Steam Deck. Here’s how to update it.
Step 1: Download XeSS
Go to Intel’s GitHub and download the latest version:
https://github.com/intel/xess/releases
Unzip the file, and open the bin folder inside.
Step 2: Replace XeSS Binaries
Now navigate to this folder on your Steam Deck:
/home/deck/Desktop/common/Expedition 33/Engine/Plugins/Marketplace/XeSS/Binaries/ThirdParty/Win64/
Inside, you’ll find four files with names matching those in the bin folder you downloaded.
Important: Before replacing, save a backup of the original files elsewhere.
Then copy the four new files from the downloaded bin folder and paste them into this folder, overwriting the originals.
Recommended In-Game Settings
With the mod and XeSS updates installed, the following settings are recommended for smooth performance:
- Upscaling (XeSS): Set to “Performance” or “Ultra Performance.” Visuals remain surprisingly good, and the FPS boost is significant.
- Shadows: You can set to Medium or High if desired—this is one of the few settings that can add a lot of visual quality without major performance impact.
- Antialiasing: Turn it off—it’s very GPU-intensive and often unnecessary on a small screen.
- Other Settings: Low or disabled, as the mod has already optimized the visuals for balance.
How to Uninstall the Mod
Uninstalling is simple.
- Navigate back to:
/home/deck/.local/share/Steam/steamapps/compatdata/1903340/pfx/drive_c/users/steamuser/AppData/Local/Sandfall/Saved/Config/Windows/ - Delete the files Engine.ini and GameUserSettings.ini
The game will recreate default versions the next time it launches.
Fix for a Too-Dark Game Experience
If you find the game too dark, even after adjusting brightness and gamma in the menu:
- Open Engine.ini
- Look for the line that says:
r.TonemapperGamma=1 - To make the game brighter, lower the number. For example:
- r.TonemapperGamma=0.9 for a slight increase
- r.TonemapperGamma=0.8 for a more noticeable effect
This can make the visuals more readable without altering overall design.
Frequently Asked Questions
Is this mod compatible with other optimization mods?
No. It’s not designed to work alongside other mods that alter the engine or config files.
Will this harm my Steam Deck?
No. All changes are software-level and completely reversible.
Can I improve FPS further?
You can try turning more in-game settings off or reducing resolution, but this guide already provides the best balance of visuals and performance.
Conclusion
Clair Obscur: Expedition 33 might not be Steam Deck-ready out of the box, but with this custom optimization mod, it absolutely can be. Enjoy responsive combat, smoother overworld exploration, and striking visuals without frustrating performance drops.
Download the mod, follow the steps, and transform your handheld experience today.
Last Updated on May 1, 2025
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