Earlier quoted context omitted.
I don't think this is true. I can go into my display settings in kde plasma and enable HDR and configure the brightness. I have a nvidia blackwell card.
You can enable, yes. But (assuming you're on an LCD display and not an OLED), you're likely still on XRGB8888 - i.e. 8-bit per channel. Check `drm_info`. Also, go to YouTube and play this video: https://www.youtube.com/watch?v=onVhbeY7nLM Do it once on "HDR" on Linux, and then on Windows. The "HDR" in nVidia/Linux is fake. The brightness you see on Plasma or Mutter is indeed related to the HDR support in the driver.…
Your Display Configuration
Both monitors are outputting 10-bit color using the ABGR2101010 pixel format.
| Monitor | Connector | Format | Color Depth | HDR | Colorspace |
|------------------------|-----------|-------------|-------------|--------------|------------|
| Dell U2725QE (XXXXXXX) | HDMI-A-1 | ABGR2101010 | 10-bit | Enabled (PQ) | BT2020_RGB |
| Dell U2725QE (XXXXXXX) | HDMI-A-2 | ABGR2101010 | 10-bit | Disabled | Default |
* Changed the serial numbers to XXXXXXXI am on Wayland and outputting via HDMI 2.1 if that helps.
EDIT: Claude explained how it determined this with drm_info, and manually verified it:
> Planes 0 and 3 are the primary planes (type=1) for CRTCs 62 and 81 respectively - these are what actually display your desktop content. The Format: field shows the pixel format of the currently attached framebuffer.
EDIT: Also note that I am slowbanned on this site, so may not be able to respond for a bit.
EDIT: You should try connecting with HDMI 2.1 (you will need a 8k HDMI cable or it will fall back to older standards instead of FRL).
EDIT: HDR on youtube appears to work for me. Youtube correctly indentifies HDR on only 1 of my monitors and I can see a big difference in the flames between them on this scene: https://www.youtube.com/watch?v=WjJWvAhNq34