Comments on: NVidia, TwinView, and OpenGL http://zaf.geek.nz/blog/2007/04/27/nvidia-twinview-and-opengl/ Thoughts from the geek Sun, 18 Jan 2009 02:36:10 +1300 http://wordpress.org/?v=2.8.4 hourly 1 By: zaf http://zaf.geek.nz/blog/2007/04/27/nvidia-twinview-and-opengl/comment-page-1/#comment-55 zaf Sun, 17 Jun 2007 10:12:06 +0000 http://zaf.geek.nz/blog/2007/04/27/nvidia-twinview-and-opengl/#comment-55 My solution above deals with allowing OpenGL to display only in one window. If, without my above changes, you still have the problem of the squished screen, then fix that problem first. If however adding that one line makes your single screen squished, check /etc/X11/xorg.conf Look at Section "Screen" And look at subsection "Display". Mine reads: SubSection "Display" Depth 24 Modes "1600x1200" "1280x1024" "1024x768" "800x600" "640x480" EndSubSection This is basically saying, first try a 1600 x 1200 (dual head) setup, then try the other modes. I'm suspecting that your X is trying for one of the non dual head modes (say 1280 x 1024). It will do this if it rejects the first option (1600 x 1200). It may reject it for many reasons, and the "easiest" way to find out is to exit out of X entirely (So goto the console (ctrl+alt+f1), login, and type sudo /etc/init.d/gdm stop). Then try running X from a console like so: # startx 2>/tmp/x.log After X starts, abort (ctrl+alt+backspace), and read x.log, looking for why X is rejecting the 1600x1200 mode (or whatever your dual head set up is). In the end, if you still can't get it working, the best advice I can give is post to the Ubuntu forums with all your system details (xorg.conf file, x.log log file, etc) My solution above deals with allowing OpenGL to display only in one window. If, without my above changes, you still have the problem of the squished screen, then fix that problem first.

If however adding that one line makes your single screen squished, check /etc/X11/xorg.conf
Look at Section “Screen”
And look at subsection “Display”. Mine reads:
SubSection “Display”
Depth 24
Modes “1600×1200″ “1280×1024″ “1024×768″ “800×600″ “640×480″
EndSubSection
This is basically saying, first try a 1600 x 1200 (dual head) setup, then try the other modes. I’m suspecting that your X is trying for one of the non dual head modes (say 1280 x 1024).
It will do this if it rejects the first option (1600 x 1200). It may reject it for many reasons, and the “easiest” way to find out is to exit out of X entirely (So goto the console (ctrl+alt+f1), login, and type sudo /etc/init.d/gdm stop).
Then try running X from a console like so:
# startx 2>/tmp/x.log
After X starts, abort (ctrl+alt+backspace), and read x.log, looking for why X is rejecting the 1600×1200 mode (or whatever your dual head set up is).

In the end, if you still can’t get it working, the best advice I can give is post to the Ubuntu forums with all your system details (xorg.conf file, x.log log file, etc)

]]> By: Jack http://zaf.geek.nz/blog/2007/04/27/nvidia-twinview-and-opengl/comment-page-1/#comment-54 Jack Sat, 16 Jun 2007 18:00:58 +0000 http://zaf.geek.nz/blog/2007/04/27/nvidia-twinview-and-opengl/#comment-54 I tried your solution but have had problems. I have Ubuntu on an AMD64 system with some old generic Jaton video card with an nvidia chipset with dual CRTs (I know, Old School). When I set the metamode option and rebooted X, I got just one monitor on and the whole desktop was squished into it. This was just logging in, not even in an open gl app. Just wanted to get the word out to see if anyone else had similar problems. I tried your solution but have had problems. I have Ubuntu on an AMD64 system with some old generic Jaton video card with an nvidia chipset with dual CRTs (I know, Old School). When I set the metamode option and rebooted X, I got just one monitor on and the whole desktop was squished into it. This was just logging in, not even in an open gl app. Just wanted to get the word out to see if anyone else had similar problems.

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