How do I change the maximum resolution of my computer Ubuntu 12.10

Question

I am trying to enable three monitors for my setup. My card is a Raedon 5700 HD series. When I try to extend my display to any additional monitors, I get the following error:

required virtual size does not fit available size: requested=(3200, 900), minimum=(320, 200), maximum=(1600, 1600)

All I should have to do is increase my maximum resolution to a larger number. How would I go about doing this?

This is my xorg.conf file. It's pretty empty. I'm not very good with Linux, so please try to explain in as simple terms as possible.

Section "Screen"
    Identifier  "Default Screen"
    DefaultDepth    24
EndSection

Section "Module"
    Load    "glx"
EndSection

Answer 1

I had the same problem, here's how I fixed it. Install the AMD/ATI driver for your video adapter (from vendor, not the default linux driver). Run the AMD Catalyst Control Center as admin. If you aren't comfortable launching from a terminal, right-click on icon in the menu and select 'add to desktop', then on desktop right-click on icon and select 'open as administrator'. In AMD CCC, click on Display Manager in nav panel, then the multi-display tab, then click the drop down arrow to the right and pick 'multi-display'. Click 'Display' tab and it should show your desktop resolution as being larger now. 'OK', it will tell you to reboot, comply with that and you should be good to go.