Triple Monitors - Single Desktop - Dual nVidia PCI-Express

[V1ND3X]

OK - here's the problem:

I'm running 2 GeForce 7600GS PCI-Express cards - each with dual DVI - which push three 20" SyncMasters (the Master card pushes the center LCD and the Slave card pushes the left and right LCDs).

I use Windows for gaming only and under which, the cards run the center screen only in SLI. However, I do everything else under Linux and I want to have a single desktop screen spanning all the monitors. I've searched extensively in forums and the nVidia documentation and can only find either dual-screen nVidia "TwinView" configurations and/or configurations which utilize disparate video cards in AGP/PCI configurations and utilize three monitors.

I have identical video cards and identical monitors so it can't be too complicated. However, I'm not quite sure which is the best way to go to get one desktop spanning all three heads.

Ideas? Thanks.

[Rick]

Twinview is only possible with dual monitor setups actually, on a single videocard.
The other way would be with xinerama, but you won't have hardware acceleration so it will be horribly slow...

I don't think there is a good solution for this, or atleast, it's possible but you won't have 1 big desktop, you'll have separate desktops for every monitor.
There is one other solution though, a matrox triplehead to go: http://www.matrox.com/graphics/en/gxm/products/th2go/digital/home.php
_________________
Have you ever noticed how stable windows is?
Neither have I

[V1ND3X]

Well, that's not cool at all... From what i've read, the TripleHead2Go Digital is capable of a maximum 3840x768 (3x 1280x768 widescreen LCDs). The idea of being able to push all three heads in SLI with such a device is tempting (especially with their "bezel management" tool).

However, my goal is to achieve a 5040x1050 desktop with hardware acceleration across all three displays.

[Rick]

What you are trying to acomplish will only be possible with 2 or 3 different X sessions. You'll be able to move your mouse around but every program would be running on that specific X session only.
For two monitors on 1 videocard you can use twinview, but the other one will be separated.
_________________
Have you ever noticed how stable windows is?
Neither have I

[seldom_used]

"Horribly slow" is not really the right word. I'm running two 7300GS cards with three LCDs, running as straight Xinerama, non-Twinview. It's perfectly fine for regular desktop apps (I've never tried to game on this setup). From what I've read on nvforums the Xinerama performance issue existed but has been largely fixed in the current nvidia drivers so I suggest you give it a try yourself. You should be able to set this up either by editing xorg.conf or with nvidia-settings.

[Rick]

[V1ND3X]

I did get all three monitors up with one desktop using Xinerama. Basically, I let X configure xorg.conf for me (by executing "X -configure") and then filling-in the Xinerama info as per the gentoo-wiki tutorials.

I agree that with a "current" hardware configuration (Intel Core2Duo 1.8GHz, 1GB ram, dual nVidia GeForce 7600GS 500MB) it wasn't "horribly slow" at all. It certainly is perfectly usable for common tasks (email, word processing, etc.) and I'd recommend it for anyone wanting to take advantage of the extra screen real estate for document work.

However, it's a deal-breaker when it comes to eye candy. It is annoyingly slow for most effects and impossible for true transparency. So... Im retiring one of the syncmasters and opting for a central 20" screen with another 20" wing utilizing TwinView.
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Abit IN9 SLI
Intel Core2Duo 1.8GHz
1GB RAM
nVidia GeForce 7600GS (Master)
nVidia GeForce 7600GS (Slave)
Western Digital 80GB SATA Harddrive

[seldom_used]

You're right when it comes to eye candy. Transparency in KDE is problematic, and Beryl won't run on Xinerama because of a bug in X relating to Composite + Xinerama. Matrox triplehead2go looks like a good solution for someone who really wants the effects.

[Rick]

Well, I found that simply scrolling a webpage made the entire pc lockup... that's not supposed to happen.
_________________
Have you ever noticed how stable windows is?
Neither have I

[V1ND3X]