Can't change output resolution from 4096x2160.

[ugafan]

The resolution being sent to my TV is 4096x2160 @ 30hz. This causes black bars on the side of the screen when playing games.

I've tried going to the game properties and changing the game resolution. I've tried checking the box for "Set resolution for internal and external display". It has no effect,
I still get 4096x2160 and the black bars.

I can change the resolution to 1080p in Desktop Mode. But if I try to change it to 720p, it doesn't scale properly and the image is zoomed in and won't fit on the screen.

[Just Following Orders]

Seeing the same issue, I suspect it has to do with the TV reporting a suggested resolution of 4096x2160 (what my Hisense is doing) or something similar. We really need an output resolution override in gaming mode, not just an override for the game level.

[MrSandman]

Just disable 'overscan' on your tv.

[Just Following Orders]

Overscan is already locked to disabled, as is control of the aspect ratio.

[MrSandman]

Have you reduced the global scale resolution in desktop mode?

[Just Following Orders]

If you mean changing the resolution in settings of desktop mode then yes, game mode seems to ignore this change.

[ProKamikadze]

+1 to discussion, it would be nice to have option to set external display resolution in gaming mode

I often plugin to 4k display, and after some time the usb-c to hdmi adapter gets hot. No doubt it affects battery and considering distance I'm from the screen, the games would look good enough in 1440p or even 1080p

[Renzuokun]

Same issue here on TCL series 5 Roku TV.

To be honest, I don't see the value in ever outputting 4096x2160. That resolution is cursed hahaha. What consumer displays actually support it?

[ka]

I found a simple solution, and it works!!!
In desktop mode, type these 3 lines on the command line:

sudo steamos-readonly disable
sudo sed -i 's/-w 1280 -h 800/-W 1920 -H 1080/g' /usr/bin/gamescope-session
sudo steamos-readonly enable

Fixed!!!

(from https://www.reddit.com/r/SteamDeck/comments/wro0s8/comment/ikua0e7/)

You can also run a script for doing this. Create a text file named "fix_hdmi.sh" with the 3 lines above.

To run the script type:
sh fix_hdmi.sh [ENTER]

sh f [TAB] [ENTER]
also works.

(or, for the Linux savvy people, just edit the gamescope-session file yourselves)


Now I can run Dirt Rally 2 on my 4k OLED with awesome picture quality and a solid 60fps.
Steam Deck HDMI output at 1080p.
LG 55BX OLED doing upscaling and sharpening.
Hard to tell from real 4k.