SteamDeck with a 4K monitor

If you want to play games like God of War or Spiderman on a SteamDeck, they look very bad on a 4K monitor with the default settings. More over, the resolution in the settings are limited to render games at 720p (for PlayStation titles, at least). The Deck verified program or ProtonDB don’t talk much about docked mode.

After some research and tinkering around, I found a way to render games at 1080p resolution, so the games look better on a bigger screen. To do this, go to the Library -> Your Game -> Settings -> Properties -> General and set the resolution to a higher value. This will let you choose resolution from the in-game settings.

With the default Graphics settings, limit games to 30fps or 40fps and they are very playable while looking great.