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Old 06-02-09, 04:17 PM   #25
AaronP
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Default Re: Projector Wall

I took a look at the video you posted, and it looks like the problem is that Xgl is not sending Expose events to its clients when they're moved across the Xinerama split. I don't know how Xgl is moving around the child windows, but you may need to modify it to send Expose events to its child windows when they're moved across the parent server's Xinerama screens.

As for other ways to set up that configuration without Xgl, I'm afraid your options are limited since the X server, as you surmised, does not support Xinerama plus Composite. SLI Mosaic is designed specifically to solve this sort of problem, but I can understand if that's outside your budget.
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Old 06-02-09, 04:24 PM   #26
mattty
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Default Re: Projector Wall

Yeah, I can't afford Quadros

I think I'm going to go with a set of Triplehead2Gos. I spent a bunch of time trying to adjust xorg.conf and nvidia-settings options that seemed like they had something to do with redrawing or damage, but it was not helpful.

I'm curious: how is SLI Mosaic implemented? A bunch of custom sauce?
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Old 06-02-09, 04:24 PM   #27
JaXXoN
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Default Re: Projector Wall

Quote:
Originally Posted by mattty View Post
Jaxxon:
You get along well with the triplehead2go box, yes?
Works like a charm for three months, now - as mentioned in the other thread
(http://www.nvnews.net/vbulletin/showthread.php?t=126134), I initially
had some timing problem with my Acer panels, but that was basically
easy to fix (as detailed in the other thread).

BTW.: the reason I was asking if separate X-Screens are strictly
necessary is that in case it also works with twinview, instead, then
I can offer you to try your compiz module with my six head dual TH2G
single GTX260 setup (on Fedora 10).

However, if you say that you also have the smearing with twinview,
then I fear it won't be any better with my setup ...

Quote:
Originally Posted by mattty View Post
I would hate to switch over and then hit some other obscure problem
There have been a couple of success reports, so far in this forum,
but I certainly can't guarantee that it will work for you.

Quote:
Originally Posted by mattty View Post
An 8-series GPU maxes out at 8192x8192 resolution according to Nvidia's documentation, I would think it could drive 3072x1536 in Twinview.
With 3x2 x 1024x768 you even shouldn't need to tweak the xorg.conf,
because the TH2G boxes have the 3072x768 EDID flashed by default.

regards

Bernhard

Last edited by JaXXoN; 06-02-09 at 08:29 PM. Reason: default EDID is 3072x768 (not 3072x1024)
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Old 06-02-09, 04:55 PM   #28
mattty
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Default Re: Projector Wall

I just want one Compiz desktop across 6 projectors. That implies one X screen, no?

Jaxxon, do you have the digital or analog model of the th2g? If you have the digital, are you able to verify for me whether dvi->vga converters work on the outputs?
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Old 06-02-09, 09:04 PM   #29
JaXXoN
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Default Re: Projector Wall

Quote:
Originally Posted by mattty View Post
I just want one Compiz desktop across 6 projectors. That implies one X screen, no?
Not necessarily: my understanding is that a window manager could be aware
of the multiple screens and render to them separately. Means: a WM could do
the same thing as xinerama, but on a higher level (no xinerama needed).

The discussion in the this (fuzzy) thread:
http://www.nvnews.net/vbulletin/showthread.php?t=133507
gives me the impression that this has already been implemented for compiz, but i
couldn't easily find any confirmation on the compiz home page or googeling the web.


Quote:
Originally Posted by mattty View Post
Jaxxon, do you have the digital or analog model of the th2g? If you have the digital, are you able to verify for me whether dvi->vga converters work on the outputs?
I have the digital version. I will try the DVI/VGA connection, tomorrow - it is supposed
to work :-)

regards

Bernhard
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Old 06-02-09, 09:42 PM   #30
mattty
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Default Re: Projector Wall

Well, I've already ordered two of the digital versions. It better work with analog output!
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Old 06-03-09, 06:40 AM   #31
JaXXoN
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Default Re: Projector Wall

Hi!

Just connected one of my Acer panels to the TH2G through a dvi->vga converter
(DVI output on the TH2G to VGA input on the LCD). It basically works, but the
Acer display doesn't recognize the 1680x1050 correctly and the picture is
distorted (did i mention those Acer panels have been very cheap?).

Anyway, I then tried to create an xorg.conf for 3072x1536 but realized that this
is *not* the default EDID mode flashed into the box! (3840x1024 is the default).

The good news is that 3072x768 mode is supported by the TH2G:
http://www.matrox.com/graphics/en/pr...solutions.html

I need to dig out the timing values for that mode and will let you know.

regards

Bernhard
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Old 06-03-09, 07:48 AM   #32
JaXXoN
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Default Re: Projector Wall

Hi!

Ok, here are my new findings:

1. The 3072x768@60Hz *is* one of the default modes stored in the TH2G by default!
However, the mode won't be effective unless you specify the modeline in the xorg.conf.

The appropriate modeline for 3072x768@60 is:
Code:
ModeLine       "3072x768"  195.00 3072 3144 3384 4032  768  771  780  806 +HSync +VSync
2. I have created an xorg.conf (attached) with the 3072x1536 resolution that works
fine with my six Acer panels where one of the LCDs has been connected trough
DVI->VGA connector. The scaling works fine in that mode. I guess you can
safely assume that the other five outputs will also work with the adaptor :-)

regards

Bernhard
Attached Files
File Type: txt xorg.conf-3072x1536.txt (2.7 KB, 54 views)
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Old 06-03-09, 10:16 AM   #33
JaXXoN
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Default Re: Projector Wall

BTW.: the xorg.conf above provides just one big screen. Since you have a
"seamless" display array, I guess that's ok for you. However in case you need
to sub-divide the display array into logical screens, then just add the following
lines to the screen section of your xorg.conf.

Code:
    Option         "TwinviewXineramaInfo"     "True"
    Option         "TwinViewXineramaInfoOverride" "1024x768+0+0, 1024x768+1024+0, 1024x768+2048+0, 1024x768+0+768, 1024x768+1024+768, 1024x768+2048+768"
regards

Bernhard
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Old 06-03-09, 12:24 PM   #34
JaXXoN
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Default Re: Projector Wall

Quote:
Originally Posted by mattty View Post
Yeah, I can't afford Quadros
Just to avoid any missunderstandings: SLI Mosaic only works for
Quadro Plex! Means: you won't get away with a bunch of cheap
Quadro cards.

SCNR

Bernhard

Last edited by JaXXoN; 06-03-09 at 07:19 PM. Reason: typo
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Old 06-03-09, 02:20 PM   #35
mattty
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Default Re: Projector Wall

Yeah, I know. I was just curious how Nvidia implements it. I.e., do they replace swaths of code that doesn't work in Xorg or if they do it some other way. Seems reasonable maybe they can extend the twinview logic to split low level drawing commands across cards in the driver.

Thanks for all your help with the th2g. I will try to post pictures/video when I am finished.
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