Re: [TCLUG:18254] Dual headed video cards

[David Wood <jbevren@yahoo.com>]

On Sun, 28 May 2000, Yaron wrote:

> X4.0 supports not only 'standard' dual-head (ie, running two seperate
> displays at once, so you have :0 and :1), but it also supports Xinerama,
> which will use both (or, in fact, all) of your monitors as one big happy
> desktop. This is supported on Matrox cards, even if you have multiple
> cards rather than a dualhead G400.

Yep.  G200 and Millenium II here.

> I guess most, if not all window managers are not
> Xinerama-aware. Enlightenment might be since Raster uses both Xinerama and
> obviously Enlightenment (;

Now, I was led to believe that some problems I was having on this system
were due to lack of xineramic support in a WM.  However, I though (imho)
that xinerama should be transparent, and the screen should appear to be one
entity.  It is, with a couple catches. (explained below)

> There are some problems with OpenGL though - xlockmode and xscreensavers
> cool 3D modes will not work too well. 

Havent tried this <:-)

> There's a Layout section in XF86Config for X4.0 in which you can arrange
> all your monitors.

(continuing from above)
What's real important, however, is that you're aware of which card is
treated as device 0 and device 1.  Originally, this system was set up with
device 0 on the right and Device 1 was "LeftOf" device 0.  However, xmms,
windowmaker, Enlightenment, and FVWM (I think I tried KDE, not sure) did NOT
like the setup.  I had to give windows a geom of +1024+0 just to get them in
the upper left corner of the LH display, and +2048+0 for the RH display.

After playing with the config file and re-assigning the RH monitor as :1,
and LH as :0, the system rather nicely works.  There are a few quirks in
Xinerama yet, but they can be worked around.  Now everyone's very happy with
xinerama, but I ended up getting too used to two 'independent' displays
in the time I was too lazy to tweak the config. :)

> No, I've not done this personally. If you want to wait about 6 months,
> I'll probably get around to getting a G400max and another monitor or
> two...

As far as supporting the second CRTC in the G400max, I have no idea.  I
havent heard anything that would convince me that it's supported, nor have I
heard anything other than the typical "token" support for 2D mode from
Matrox.  It's important that you notify _matrox_ that you want support for
3D and dual-display mode on the G400.  While telling us doesnt tell Matrox
anything, it might encourage the list to let Matrox know what's going on. 
Dualhead and 3D support would definately sell a G400 to me.

-David