System information
- SteamOS version: 3.8.11 (Stable channel)
- Mode: Game Mode
- GPU: AMD Radeon RX 9070 GRE
- CPU: AMD Ryzen 5 5600
- Display: TCL TV connected via HDMI 2.1
- HDR enabled
- VRR enabled
Issue description
When using HDR in Steam Game Mode, I observe severe color banding in gradients (for example skies, fog, dark scenes, and other smooth HDR transitions).
The issue occurs in native HDR games and is not limited to SDR-to-HDR conversion.
The banding is visible only in Steam Game Mode. I do not observe the same issue when using HDR outside of Game Mode.
Troubleshooting performed
I tested the following configurations:
4K 120 Hz HDR YV 4:2:0
1440p 120 Hz HDR YUV 4:4:4
VRR enabled
Multiple native HDR games
The banding remains present regardless of resolution or color format.
Because the issue also occurs at 1440p YUV444, it does not appear to be related to HDMI bandwidth limitations.
Workaround
Enabling the following setting completely removes the HDR color banding:
Settings → Developer → Force Composite
With Force Composite enabled:
- HDR gradients become smooth
- Color banding disappears
- Image quality looks correct
However, performance is slightly reduced. In my testing, framerate drops from approximately 60 FPS to 57 FPS.
Expected behavior
HDR image quality should be identical regardless of whether Gamescope is using the direct scanout path or the composited path.
Actual behavior
HDR color banding is present during normal Game Mode operation, but disappears when Force Composite is enabled.
This suggests there may be an issue in the direct scanout/direct flip HDR presentation path on AMD hardware.
Additional notes
This issue is not present when outside of game mode (KDE Plasma Steam desktop session), when KDE is set to HDR and the game is started with proton HDR launch options.
System information
Issue description
When using HDR in Steam Game Mode, I observe severe color banding in gradients (for example skies, fog, dark scenes, and other smooth HDR transitions).
The issue occurs in native HDR games and is not limited to SDR-to-HDR conversion.
The banding is visible only in Steam Game Mode. I do not observe the same issue when using HDR outside of Game Mode.
Troubleshooting performed
I tested the following configurations:
4K 120 Hz HDR YV 4:2:0
1440p 120 Hz HDR YUV 4:4:4
VRR enabled
Multiple native HDR games
The banding remains present regardless of resolution or color format.
Because the issue also occurs at 1440p YUV444, it does not appear to be related to HDMI bandwidth limitations.
Workaround
Enabling the following setting completely removes the HDR color banding:
Settings → Developer → Force Composite
With Force Composite enabled:
However, performance is slightly reduced. In my testing, framerate drops from approximately 60 FPS to 57 FPS.
Expected behavior
HDR image quality should be identical regardless of whether Gamescope is using the direct scanout path or the composited path.
Actual behavior
HDR color banding is present during normal Game Mode operation, but disappears when Force Composite is enabled.
This suggests there may be an issue in the direct scanout/direct flip HDR presentation path on AMD hardware.
Additional notes
This issue is not present when outside of game mode (KDE Plasma Steam desktop session), when KDE is set to HDR and the game is started with proton HDR launch options.