Set your resolution in the config.cfg file located under this directory: ~/.steam/steam/steamapps/compatdata/20880/pfx/drive_c/users/steamuser/My Documents/American Truck Simulator/ My example: uset r_mode_refresh "165" uset r_mode_height "1080" uset r_mode_width "1920" And set these to 1-2k each uset t_averaging_window_duration "2000" uset t_averaging_window_length "2000"

OpenGL is just terrible, I would average 40-60FPS. I tried out Proton.9.0-1, and it had some FPS and stuttering issues. GE-Proton.9-6 vastly improved stability, and increased my FPS to 70 in large cities, and up to 120FPS in rural areas. My framerate stays above 60FPS and never drops below. Overall, this was better than what I was expecting.