How does one configure the Radeon Open Source drivers? I have just installed Ubuntu 12.10 and want to try the Open Source drivers instead of the proprietary AMD binaries. After the installation, the driver seems to be installed, I have wobbly windows working (can't use a PC without wobbly windows!), and life is generally good.

I have a problem when I connect a secondary monitor. Performance is killed (everything becomes laggy and jerky) and my laptop sits on the right-hand side of the monitor, not the left.

I'd like to know how to turn off the Laptop's monitor so I'm just using the external monitor. How can I do this using the Open Source Radeon drivers? I can't find a GUI management tool, and there's no longer an xorg.conf. What to do?