Having setup my SUSE Linux Enterprise Desktop 11 on Thinkpad T61p working with Xen previously [link here], I now needed to project my screen (1920x1200) onto an external projector (typically 1024x768). Additionally, I have an external LCD monitor which I would like to use as my secondary monitor (ie Multi-head, desktop spanning blah).
Good news is it WORKS!
Here are my observations and the neat little trick (tool) that worked for me:
Note: After plugging in the VGA cable to Thinkpad T61p, always restart (re-initialized) X11 (Ctrl-Alt-Backspace) before doing anything else. On SLED 11, you will need to hit Ctrl-Alt-Backspace TWICE within 1-2 seconds. I think this is a newly introduced safety feature to avoid accidentally hitting this key combination and killing the entire X11.
1) SAX2 in SLED 11 does not seem to drive the nVidia driver like it used to do in SLED 10, especially the part where we configure Dual Head Mode. Irregardless of how I tried to configure the Dual Head Mode settings in SAX2, when I connect to an external projector or LCD monitor and after re-initializing X11, SLED 11 will project itself onto the external display and my Thinkpad LCD will be blank.
2) The trick to get the display to show on both the Thinkpad LCD (1920x1200) and external screens in the correct resolution is to use the nVidia tool that comes with the driver. As root, you startl it up via nvidia-settings. Below are 2 screenshots of it in action. I run it as root so that any changes I made can be written to the xorg.conf file directly.
If I had an external screen connected to my Thinkpad T61p as I'm writing this, the second screenshot would have 2 screens set side-by-side for me to configure the resolution, position and designate the primary display when using the TwinView mode.
Of course, the SLED 11 3D desktop effects continue to work across screens. Very sweet... so sweet that my good friend, a loyal Windows Vista user and graphics guru, is impressed.