VESA defined modes are - 320×200 - 640×400 - 640×480 - 800×600 - 1024×768 - 1280×1024 No idea whether the vesa driver supports non-vesa modes, but did you try using nouveau instead of vesa? /var/log/Xorg.0.log will tell you the servers opinion on what you added to your config. Cheers, Thomas