Multiple screens.

Peter Ankerstål uchman at
Mon Apr 4 14:13:40 PDT 2005

On Mon, 4 Apr 2005 17:05:38 -0400
Alex Deucher <alexdeucher at> wrote:

> On Apr 4, 2005 4:53 PM, Peter Ankerstål <uchman at> wrote:
> > 
> > >
> > > Yes, crtc1 is driving both displays.  both the LCD and the VGA port
> > > are getting the same mode, probably 1024x768 at 60hz.  If you want to run
> > > the LCD at say 1024x768 at 60hz and the VGA port at say 1280x1024 at 75hz,
> > > you will need to program both crtcs (crt/display controllers); one for
> > > each output.  if you just want to use one crtc to drive either the vga
> > > port or the lcd, there's not really an easy way to use modes beyond
> > > the capabilites of the attached monitors after X is started.
> > >
> > If i start two x-sessions I can run one on each screen. The one i run in
> > 1024x768 Is on both screens because both screens support it. And the other session
> > runs 1280x1024 And is only displayed on the external screen. (1280x1024 is not
> > supported by the internal screen).
> > It must be a way to do this but with only one x-session.
> > 
> the only way to do simultaneous 1280x1024 on the vga port and 1024x768
> on the LCD is with 2 crtcs.  the chip supports that, but the driver
> does not.  one thing you could try is to start X on the vga port at
> 1280x1024 and then use xrandr or cntl-alt-+/- to switch the mode to
> 1024x768 and then use the bios fn key combination to switch the
> display to the vga port and the lcd port, be careful though to make
> sure you are using a 1024x768 mode that your lcd can handle (probably
> 60Hz). YMMV...
> Alex
I've tried that. But it doesnt work at all. :/. 

Peter Ankerstål.

More information about the xorg mailing list