DisplayPort only outputs 640x480 to a 4K monitor

[danikei]

When connecting the Steam Deck Dock via DisplayPort to my LG31MU97 monitor it doesn't show any other resolution than 640x480 in settings (won't work in auto either).

The native resolution of the monitor is 4096x2160 which isn't supported by the Steam Deck, so my guess is that maybe because of that the EDID isn't read correctly via DisplayPort? If I connect it via HDMI it is able to display up to 2K@60, so I was hoping to get the same via dp.

Just in case it's this, I tried forcing a 1920x1080 resolution via de DP in Desktop Mode and it actually works. However its a temporary solution, since once I get out of Desktop Mode (or restart) it loses the added resolution.

One of the main reasons I got the official dock was the displayport output (since I'm using my hdmi ports in the monitor) but like this for me it's unusable. For now I think I have to wait for valve to implement a way to force resolutions to the displayport or fix how it reads EDID (don't have this problem with anything else). Or maybe somebody can create a DeckyLoader plugin?

[Recluta.Рэклута]

I have an Asus ROG SWIFT PG278Q display which only has a DP connection and I'm having the same issue as you connecting a DP to USB-C directly to the Steam Deck, the resolution it displays is 480p so I really thought the dock with a DP connection would solve the problem but I can see this is not the case.

I'll try to come up with other solutions and let you know if I find something.

[The Green Nerd]

Same issue here. Display Port isn't working in game mode. In desktop mode only 3440 * 1440 @ 60hz. @ 100hz, it gives me a black screen. Returning to Gaming mode gives me a black screen again.

HDMI on my 34" widescreen is a whole other story. Game mode works fine. But desktopmode gives me a static image.

Solution in desktop mode: expand or double Steam Deck and change the output on the screen of the Deck
Solution in Game mode: sue an HDMI cable (maybe save resolution mode? need to test this).

Seems Valve have still has issues with there dock mode. Sometimes if feels we are beta-testers (which I don't mind, but the Dock is a bit expensive to be a beta product).

[danikei]

so basically depending on the monitor the displayport output is basically useless... weird, while the hdmi out works normally. I hope they release a firmware update to fix it...

[danikei]

For anyone who wants to try it, the issue is fixed on my monitor after applying the latest steam deck and steam deck dock firmware update :) I couldn't test it much but it seemed to be working as expected. For anyone wondering I'm on the preview channel, just in case it changes anything.
So happy the keep pushing fixes, good job valve!