[gentoo-user] Xinerama and Xrandr

[gentoo-user] Xinerama and Xrandr

[Dan Johansson]

I have been playing with my X-configuration this weekend and I can not really 
get it to work the way I like. My desktop box has two Nvidia cards installed 
with one monitor connected to each. On to of that I am running KDE (v 4.3.5 at 
the moment).

# lspci | grep VGA
01:00.0 VGA compatible controller: nVidia Corporation G86 [GeForce 8400 GS] 
(rev a1)
05:00.0 VGA compatible controller: nVidia Corporation G86 [GeForce 8400 GS] 
(rev a1)

If I have "Option Xinerama on" in the ServerLayout section in xorg.conf then 
KDE uses both monitors (in Xinerama "mode") but I can not use any "Desktop 
effects" as "Compositing is not supported". Also a lot of GUI programs reports 
"Xlib:  extension "RANDR" missing on display ":0.0"."

If I set "Option Xinerama off" in xorg.conf then KDE only "runs" on one of the 
monitors and the "Desktop effects" works great. And the other GUI's does not 
give me that Xlkib error message.  But now the only way to start a GUI on the 
second Monitor is to prefix it with DISPLAY=:0.1 or use --display :0.1.

Does someone have any suggestion how I can "get the best of both worlds"?
i.e. Compositing && KDE using both monitors.

-- 
Dan Johansson, <http://www.dmj.nu>
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This message is printed on 100% recycled electrons!
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[gentoo-user] Re: Xinerama and Xrandr

[Allistar]

Dan Johansson wrote:

> I have been playing with my X-configuration this weekend and I can not
> really get it to work the way I like. My desktop box has two Nvidia cards
> installed with one monitor connected to each. On to of that I am running
> KDE (v 4.3.5 at the moment).
> 
> # lspci | grep VGA
> 01:00.0 VGA compatible controller: nVidia Corporation G86 [GeForce 8400
> GS] (rev a1)
> 05:00.0 VGA compatible controller: nVidia Corporation G86 [GeForce 8400
> GS] (rev a1)
> 
> If I have "Option Xinerama on" in the ServerLayout section in xorg.conf
> then KDE uses both monitors (in Xinerama "mode") but I can not use any
> "Desktop effects" as "Compositing is not supported". Also a lot of GUI
> programs reports
> "Xlib:  extension "RANDR" missing on display ":0.0"."
> 
> If I set "Option Xinerama off" in xorg.conf then KDE only "runs" on one of
> the monitors and the "Desktop effects" works great. And the other GUI's
> does not
> give me that Xlkib error message.  But now the only way to start a GUI on
> the second Monitor is to prefix it with DISPLAY=:0.1 or use --display
> :0.1.
> 
> Does someone have any suggestion how I can "get the best of both worlds"?
> i.e. Compositing && KDE using both monitors.

You cannot do compositing or XRandR and Xinerama at the same time. Each of
those NVidia cards has two outputs. One approach is to only use one of the
cards and us NVidia's TwinView, which gets around having to use the
Xinerama extension. Then you can have a single big desktop spanning both
monitors, and the eye candy of desktop effects.