I’ve got a 1440p monitor but a crappy laptop not great for gaming. I wanted to play Portal 2 at 1920×1440 (1440p in 4:3) as I want better performance than 16:9 1440p, is there a way to set a custom resolution in Steam or console commands? I’ve tried both, but it either defaults to 1920×1200 for some reason, or I can’t find the right command.

I don’t know why this resolution isn’t already available in the video options, but I would like to try it out. I sit pretty close to my monitor as well so having everything more central in 4:3 makes everything easier to see.