Linux & HDR

Current state of HDR

HDR on Linux has come a long way, from basically an impossible task to now a workable HDR experience. Saying this, HDR on Linux still has a long way to go, as it does not have a plug-and-play experience yet. For most gaming experiences, it works flawlessly, however.

What is working in regard to HDR:

You can turn on HDR in your DE (Currently KDE & Gnome)
You can play local HDR videos using a video player (Currently only on MPV)
You can play HDR videos in Firedragon 12+ (with the caveat that if the browser HDR setting is enabled, SDR videos do not work)
You can play games in HDR (Works across any recent mainline or fork of Proton)

What is NOT working in regard to HDR:

You can’t take HDR screenshots
You can’t record HDR videos
You can’t play SDR videos in Firedragon 12+ when the browser HDR setting is enabled
You can’t play HDR videos in most of the browsers (except the latest Firefox and its forks with the caveat above)

Three main conditions are needed in order to use HDR:

You need to have an HDR capable monitor
You need to have a DE with HDR support
You need to use Wayland

The point of this article is to share information on the HDR options and, if possible, the best settings (or guide to configuring the settings) for non-HDR + HDR settings in supported DEs.

Monitor Settings

For the purposes of this wiki article, the following hardware was used to demonstrate:

Monitor AW3423DWF
GPU 9070XT

For when HDR is disabled, there are 2 profiles to consider.

The first one will cap the color space to sRGB, but it will be the most accurate representation of white balance, colors, and color temperature.

Color accuracy - Pure sRGB - Creator > sRGB + Gamma 2.2 You can also set P3, but it does not matter, because we will always keep HDR in KDE ON. If you disable HDR and want more colors, P3 in pure SDR is good. Also, it is very important to point out that the monitor used to create this article, “AW3423DWF”, is factory calibrated for sRGB and P3 out of the box. This may not be true for every monitor.

The second one will be less accurate in regard to colors and white balance but will give you more vivid colors. Yet still will keep more true to real colors than the Standard preset.

Vivid colors - Less accurate - Custom > Gain > 97-98-100 The gain is different for each monitor. There are no universally applicable settings.

Rest of the settings:

Everything else is off/default
Brightness/Contrast both at 75%
HDR modes:
- Peak 1000 - HDR1000
- True Black - HDR400

KDE Plasma

KDE Plasma probably has the easiest HDR experience, as the devs integrated HDR into the DE directly. To turn on HDR is as easy as clicking one option in the settings.

System settings → Display & Monitor → High Dynamic Range → Enable HDR → Apply

KDE display settings with Enable HDR checked

HDR settings & options

When HDR is enabled, 2 new settings/options appear in the Display & Monitor menu:

Calibrate HDR Brightness
sRGB Color intensity

With enabling HDR you most likely will ask yourself 3 questions:

What are those extra options for?
Why are the colors so flat, ugly, washed out and dim?
How should I use them?

What are those extra options for?

Calibrate HDR Brightness

Peak HDR luminescence (which displays often report wrong)

This shows a white square covering 10% of the display area at 10000 cd/m² (which the monitor limits to the maximum it can actually show), and the Plasma logo at a luminescence level configured by the user.
- Adjust the brightness level so the Plasma logo is barely visible.
Max SDR luminescence (previously known as maximum SDR brightness)

This option changes what “100%” of the normal brightness slider means and needs to be configured
- low enough so that the monitor’s tone mapping doesn’t interfere with image quality
- low or high enough to match user preference
Summary & Windows app option

This option shows the to be applied HDR calibration settings. Additionally it allows the user to choose which screen or rather which calibration Windows applications on the system can be assumed to be calibrated towards.
- Review summary
- Allow Windows application to have their own calibration settings work in Plasma

sRGB Color intensity

This option is inspired by the color slider on the Steam Deck. For sRGB applications, it scales the color gamut up to (at 100%) rec.2020, or, more simply put, it makes the colors of non-HDR apps more intense to counteract the bad gamut mapping many HDR displays do and makes the colors of SDR apps look more like when HDR is disabled.

Why are the colors so flat, ugly, washed out, and dim?

The answer is rec.2020.

When you enable HDR, it does not use sRGB, P3, or other monitor preconfigured color spaces. It uses the proper HDR rec.2020 color space. In HDR content, this color space will make life shine bright and colorful. However, the problem is the DE and the non-HDR content will have “washed out colors” and your screen may look “dim”.

In order to combat that, we can use the sRGB Color Intensity & Calibrate HDR Brightness options.

How should I use them?

It depends on personal preferences and the capabilities of your monitor. The below settings will try to provide a sweet spot for HDR enabled + HDR content + SDR content. Basically the intent is to tune the visual to the same level as the SteamDeck OLED. This is because the Steam Deck OLED has very vivid yet not so much over-saturated colors out of the box.

This HDR mode and settings should give you the best experience for peak highlight brightness. It really makes the details !POP! like: fire, explosions, etc.

The downside to this is something called ABL. Some people do not see it, some do, and it mainly depends on the content you are using it on. For example, when you have a darker scene, ABL will not kick in. But if you have a brighter scene, ABL will kick in, and the overall picture may look a bit dim compared to when HDR is turned off. This will be more visible in SDR.

If that’s the case, and you still want to use HDR, you can use the True Black - HDR400 mode.

HDR enabled
Color accuracy - Prefer efficiency The other mode has a performance impact
sRGB Color Intensity ~55%
Calibrate HDR Brightness
- Peak HDR luminescence - 970 nits
- Max SDR luminescence - 250 nits
- Summary & Windows app option - Windows applications option checked
Brightness 75%

How to enable HDR in games

You need to install gamescope
Add the following to the game’s Launch Options in Steam:
- -w -h changes the resolution, and should be set to your monitor’s native resolution
- -f enables fullscreen
- -r changes the refresh rate, and should be set to your monitor’s refresh rate
- --adaptive-sync enables VRR, should be set if the monitor supports it and it’s enabled in KDE
- --hdr-enabled enables HDR
Terminal window
```
gamescope -w 3440 -h 1440 -f -r 165 --adaptive-sync --hdr-enabled -- %command%
```

Troubleshooting

Performance issues

1. Game & Camera stutter

kwin-effects-better-blur-dx (legacy)

In case you see weird camera or game stutter, try to disable kwin-effects-better-blur-dx or put gamescope into the exclusion list. I tested as well games without gamescope and looks like the issue is present as well there.

To fix this you have 3 possibilities:

Disable Better Blur DX

Settings > Windows manager > Desktop Effects > Disable Better Blur DX > Apply
GAMESCOPE ~ Exclude gamescope from Better Blur DX

Settings > Windows manager > Desktop Effects > Go to settings in Better Blur DX > Go to Force Blur > add into the list gamescope > enable Blur all except matching > Apply
NON-GAMESCOPE ~ Exclude Steam games from Better Blur DX

_Settings > Windows manager > Desktop Effects > Go to settings in Better Blur DX > Go to Force Blur > add into the list /(steam_app_[0-9]\*)/ > enable Blur all except matching > Apply_

References

https://zamundaaa.github.io/wayland/2023/12/18/update-on-hdr-and-colormanagement-in-plasma.html

https://invent.kde.org/plasma/kscreen/-/merge_requests/365#note_1189680

https://zamundaaa.github.io/colormanagement/2025/03/31/about-brightness.html

https://wiki.archlinux.org/title/HDR_monitor_support#With_Gamescope