Three monitors -- Is it doable? [nVidia]

geeksunny · 2012-04-25 06:44:32

First off, let me say I think / hope I am in the right forum section. I couldn't decide if this was a hardware or software question, but since it has more to do with the drivers and software, I decided to put it in here. If I am in the wrong section, though, I ask that a Mod please move this to the correct one. Also, I did a quick search of the forum before posting and couldn't find any similar threads. Apologies if this has been asked before. (Sorry for all this humbling rules talk but as this is my first post, I want to make it clear that I am a civilized user!)

Anyway -- now for the question!

On my main PC I run three 19" displays, which are connected to two nVidia GTX 275. I am currently running Windows 7 and would like to switch over to Arch for the majority of my computing needs. I have ran Arch prior on just one video card and two monitors. Back when I made the leap to 2 cards/3 monitors, I encountered a lot of X crashes and funky behavior with my desktop environments. As it's been quite a while since I was fiddled with it, I was wondering if anyone else has had any luck with this configuration and had any pointers for me to try out.

As for my expectations...

I'd like to use Gnome 3, preferably with the Cinnamon shell replacement but Gnome-Shell will also work.
If Gnome 3 is a no-go, I would then prefer XFCE, hopefully with a functional Compiz setup.
If that won't work, I would be okay with using KDE. I'm not much of a fan, though.

Back when I had first played around with this setup, I was using the official nVidia drivers and running Gnome-Shell. I forget the exact xorg configuration setups I was using, but some times it would "work" with one display being normal, and the other two had a single monitor's content stretched across them. Other times it would just function like a two-monitor setup and ignore the third one completely. Both situations persisted when I tried Gnome3's Fallback mode as well.

It might be worth noting that the last time I saw a 3-monitor Linux setup working up close was my friends using Gnome 2.x and not using Compiz. I'd even be okay with using this, but I can't find an easy way to get back to Gnome 2.x that doesn't involve messing with long-abandoned / buggy code forks.

But anyway.... I think thats all I have for now. Thanks for reading, and I am looking forward to any responses!

Cloudef · 2012-04-25 06:59:35

Not really. Multi-monitor support on Linux is quite PITA. With Nvidia you are fine with 2 monitors and twinview. If you use more, then you need to use Xinerama which won't work with composition and you won't have hardware acceleration.

http://nouveau.freedesktop.org/wiki/MultiMonitorDesktop
Nouveau might work better if you hook all the monitors to single card and it will use RandR. With multiple cards you are back to xinerama route.

Wayland is supposed to fix this mess, so you might want to wait few years. Or use linux with xinerama without hw accel.

Edit: One more way to go would spawn X server on each monitor.
This should give acceleration, but you can't move windows beetwen screens (technically you can with 'xmove' tool, dunno how well it works)
http://en.gentoo-wiki.com/wiki/X.Org/Du … le_screens
This might be the best workaround so far.

Last edited by Cloudef (2012-04-25 07:09:25)

geeksunny · 2012-04-26 02:23:23

Interesting. Thanks for your reply. The single video card route isn't an option for me with the 3 monitor setup, as both of my cards only have two DVI ports and nothing more.

The multiple x-servers route might be a good way to go. I had read somewhere that they achieved 3-monitors with compiz by connecting two monitors with TwinView and the third was a separate x-server. That could be the route I take.

Thanks again!

egon2003 · 2012-04-26 11:01:43

If you use GTX 680 you can use nvidias twinview as this card supports 3 monitors. I use it myself under gentoo and it works fine.

geeksunny · 2012-05-01 05:43:26

Well I did a little research and it turns out there's a driver feature I just learned off called 'Base-Mosaic'. This will get me a 3d-accelerated desktop using all 3 of my monitors.

I wanted to test this a little before I upset my existing Windows 7 setup by re-partitioning, so I installed the latest Ubuntu using Wubi. I got a working xorg.conf rigged up and it worked great in the login screen and a stock 2d XFCE! But then it started to get buggy in Unity -- both 2d and 3d -- so I can't be sure if I should blame the nvidia/Xorg config, or Ubuntu/Unity... so I will be re-partitioning my hard drive and setting up a fresh Arch install to test this further!

For reference, here is the line I used to set up this mosaic X-layout:

nvidia-xconfig --base-mosaic --metamodes="GPU-0.DFP-1: 1440x900+0+0, GPU-0.DFP-0: 1440x900+1440+0, GPU-1.DFP-0: 1440x900+2880+0"

I will update this again when I have more to share!

egon2003 wrote:

If you use GTX 680 you can use nvidias twinview as this card supports 3 monitors. I use it myself under gentoo and it works fine.

Thanks, good to know! I can't see myself upgrading anytime soon though. Haha.

jarshvor · 2013-06-27 18:44:36

geeksunny wrote:

Well I did a little research and it turns out there's a driver feature I just learned off called 'Base-Mosaic'. This will get me a 3d-accelerated desktop using all 3 of my monitors.
I wanted to test this a little before I upset my existing Windows 7 setup by re-partitioning, so I installed the latest Ubuntu using Wubi. I got a working xorg.conf rigged up and it worked great in the login screen and a stock 2d XFCE! But then it started to get buggy in Unity -- both 2d and 3d -- so I can't be sure if I should blame the nvidia/Xorg config, or Ubuntu/Unity... so I will be re-partitioning my hard drive and setting up a fresh Arch install to test this further!
For reference, here is the line I used to set up this mosaic X-layout:
nvidia-xconfig --base-mosaic --metamodes="GPU-0.DFP-1: 1440x900+0+0, GPU-0.DFP-0: 1440x900+1440+0, GPU-1.DFP-0: 1440x900+2880+0"
I will update this again when I have more to share!
egon2003 wrote:
If you use GTX 680 you can use nvidias twinview as this card supports 3 monitors. I use it myself under gentoo and it works fine.
Thanks, good to know! I can't see myself upgrading anytime soon though. Haha.

Hi geeksunny.

Did you manage to get Mosaic mode working for your 3 monitors?
I'm currently trying to do the same across my onboard nforce graphics and my GT630.

alphaniner · 2013-06-27 18:59:14

geeksunny hasn't posted since May 2012, so I wouldn't hold my breath for a response.

ewaller · 2013-06-27 19:07:23

This is an old thread and a lot has changed in the last year. I am going to go ahead and close this thread. jarshvor, feel free to open a new thread and, if you feel this thread is still appropriate, go ahead and link back to this thread. We do this to keep confusion down between the old way of doing things and newer ways of doing things. Thanks.

Arch Linux

#1 2012-04-25 06:44:32

Three monitors -- Is it doable? [nVidia]

#2 2012-04-25 06:59:35

Re: Three monitors -- Is it doable? [nVidia]

#3 2012-04-26 02:23:23

Re: Three monitors -- Is it doable? [nVidia]

#4 2012-04-26 11:01:43

Re: Three monitors -- Is it doable? [nVidia]

#5 2012-05-01 05:43:26

Re: Three monitors -- Is it doable? [nVidia]

#6 2013-06-27 18:44:36

Re: Three monitors -- Is it doable? [nVidia]

#7 2013-06-27 18:59:14

Re: Three monitors -- Is it doable? [nVidia]

#8 2013-06-27 19:07:23

Re: Three monitors -- Is it doable? [nVidia]

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