Bug 39901 - 4 monitors on two graphic cards GeRorce 450 does not work
Summary: 4 monitors on two graphic cards GeRorce 450 does not work
Status: RESOLVED FIXED
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/nouveau (show other bugs)
Version: unspecified
Hardware: x86 (IA32) Linux (All)
: medium normal
Assignee: Nouveau Project
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-08-07 08:09 UTC by Vaclav
Modified: 2011-08-11 13:33 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Attachments
config files, logs and pictures of configuration (1.43 MB, application/zip)
2011-08-07 08:09 UTC, Vaclav
no flags Details

Description Vaclav 2011-08-07 08:09:32 UTC
Created attachment 50013 [details]
config files, logs and pictures of configuration

Hi,
I am unable to create a working configuration with 4 monitors on 2 GeForce 450 (dual headed). I am able to make it working with 3 monitors - see xorg.conf.tripple. The log file is xorg.0.log.tripple. The configuration works also with Xinerama - see monitor-tripple.jpg.

When I add 4th display into the configuration (the same way as 2nd and 3rd) the X doesn't start - see xorg.conf.quadro. No specific error message in the system or xorg log - see xorg.0.log.quadro.
 

I also tried to configure it with proprietary nvidia drivers - I can start X with 4 separate screens, but as soon as I enable Xinerama, the desktop is "shifted" to the most right monitor and I must click on the first monitor to be provided on the last one (even for two monitors) - see monitor-nvidia.jpg (selection is on right monitor, a mouse cursor on the left one - so there is an offset of a whole monitor). With 4 monitors the offset is 3 monitors :-( 

So, I see it as a bug that I am not able to enhance a working dual configuration into quadro one. Neither with nvidia nor nouveau drivers. 


I have this config:

X version:
X.Org X Server 1.10.1
Release Date: 2011-04-15
X Protocol Version 11, Revision 0
Build Operating System: Linux 2.6.24-27-server i686 Ubuntu
Current Operating System: Linux harfa 2.6.38-10-generic-pae #46-Ubuntu SMP Tue Jun 28 16:54:49 UTC 2011 i686
Kernel command line: BOOT_IMAGE=/boot/vmlinuz-2.6.38-10-generic-pae root=UUID=2e66a48e-ff81-4e7f-8a24-b4f5dd2425a4 ro vmalloc=512M quiet splash vt.handoff=7
Build Date: 21 May 2011  11:38:35AM
xorg-server 2:1.10.1-1ubuntu1.1 (For technical support please see http://www.ubuntu.com/support) 
Current version of pixman: 0.20.2
	Before reporting problems, check http://wiki.x.org
	to make sure that you have the latest version.

lspci:
01:00.0 VGA compatible controller: nVidia Corporation GF106 [GeForce 450 GTS] (rev a1)
01:00.1 Audio device: nVidia Corporation GF106 High Definition Audio Controller (rev a1)
02:00.0 VGA compatible controller: nVidia Corporation GF106 [GeForce 450 GTS] (rev a1)
02:00.1 Audio device: nVidia Corporation GF106 High Definition Audio Controller (rev a1)

Regards
Vaclav
Comment 1 Emil Velikov 2011-08-07 09:28:12 UTC
Hi Vaclav

There was a bug [1] in xf86-video-nouveau that was causing this issue and the patch that resolves [2] it can be found in the master branch

Can you please update/rebuild and give it a try

On top of that you can also try more minimalistic xorg.conf [1]

I hope it helps

Cheers
Emil

[1] https://bugs.freedesktop.org/show_bug.cgi?id=39099
[2] http://cgit.freedesktop.org/nouveau/xf86-video-nouveau/commit/?id=de9d1ba7efeba64f319efa00df183d3cb78f24af
Comment 2 Vaclav 2011-08-11 12:38:38 UTC
Hi,
Yes, now it works. Even some active elements (like flash on websites) are terrible slow - much more slower than with TwinView. 

Anyway, thanks a lot!
Vaclav
Comment 3 Emil Velikov 2011-08-11 13:33:25 UTC
I'm not 100% sure so don't take my word for it

The reason for the slowness is because compositing/acceleration does not work with xinerama

There has been a patch recently in the xserver that allows for xinerama to be used in conjunction with compositing. Nevertheless there could be some bits in nouveau that need updating

In either case you will not get any acceleration if the total resolution exceeds 4096x4096


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