Please tell me Linux supports more than 2 monitors...

[Red Squirrel]

I just bought a 3rd monitor, but I can only get 2 to work. The 3rd one shows as "disabled" in the Nvidia X server settings. I really hope this is an easy fix. Is there a way to get it to show up? Normally I'd just click twin view but that's grayed out. I only have the option to make a separate X session which I rather not play with, it's not what I want anyway. I just want a simple span between 3 monitors with the middle one being primary. Right now I have the left and middle one working but not the right. The right is on the other video card. I really have a bad feeling this is not supported. Am I screwed? I really don't want to be stuck going back to Windows. But I want 3 monitors. In fact I eventually want to go to 4, that's why I bought two video cards.

Not finding much online, either, surprisingly.

 

[Paperlantern]

How is this configured? Are both video cards the same? Are you running one different model? Honestly Ive never done more than 2 on linux so im not sure, but Id think it would be POSSIBLE.

 

[Red Squirrel]

Two idential cards, and they show up. It even detects the monitor.




The 3rd monitor is on the 2nd card. The big one is the new monitor. If I click on configuration I have the option to make it a separate X server (which I don't want to do) but not Twinview as it's grayed out.

From what I'm reading online it's looking pretty grim, but it's all old stuff, so I'm really hoping things have changed.

Edit: Tried the separate X session just to see what would happen. It DID enable it as a separate X session but then everything else went to hell. It basically started to treat the two monitors as one, and I also lost the start menu, and everything was opening half way through both screens. Terrible. Good thing I had backed up the xorg.conf. Not going to try THAT again.

 

[Cerb]

I just bought a 3rd monitor, but I can only get 2 to work. The 3rd one shows as "disabled" in the Nvidia X server settings.

What happens with Nouveau or nv? IE, you really want to be able to use KDE's systemsettings application.

 

[Red Squirrel]

Well this sucks, I totally trashed my installation. Even restoring the xorg.conf file aint doing anything. There must be some other stuff it did. I had found a xorg.conf file on the internet where it supposedly worked so I was trying to configure mine the same way keeping my stuff in mind like the PCI slot of the cards. Now it just boots me back to the login screen when I try to log in. Completely trashed. Need to reinstall.

I'm in Windows now, took ohh, 10 seconds? To get 3 monitors to work. As much as I'll miss some aspects of Linux such as speed and the fact that windows don't open all over the place like they do in Windows, I'm strongly thinking of just dumping Linux and going back to Windows. It's retarded that something as basic as triple monitor is rocket science under Linux.

 

[Red Squirrel]

What happens with Nouveau or nv? IE, you really want to be able to use KDE's systemsettings application.

Too late to try now... but I was also reading on an app called Xinerama, but it does not seem to be available under my distro. Is there something else I could try?

I'm strongly debating just sticking to windows now though, I really don't feel like reinstalling and reconfiguring everything, which I have to do now that I trashed my install.

 

[Cerb]

Too late to try now... but I was also reading on an app called Xinerama, but it does not seem to be available under my distro. Is there something else I could try?

I seek out FOSS-friendly hardware, so haven't used Geforces with multiple monitors in Linux, but I've had no problems using KDE's GUI (even if not running KDE) to set it up with Intel and AMD (FOSS, 2+ generations old AMD GPU, if possible).

 

[Red Squirrel]

Is there a way I can launch the kde app within the login screen? What is the app called? The login screen is the only GUI I have access to now. If I try to login it just boots me back to the login screen, even after restoring a xorg.conf file from before I touched anything. I can't believe it's this complicated. I really don't want to go back to Windows but I'm leaning more and more towards that. What would be FOSS friendly hardware? That would mean I need to spend even more money though, and wait for it to ship.

 

[Red Squirrel]

I managed to get in with root, so determined it was a profile issue, so I just did a backup of my profile and deleted everything that started with .x and .X and I can get in now.

The Nouveau installation seems quite involved, I will hold off on that tonight, with my luck there will be tons of dependencies and crap to deal with. That's usually how it goes.

I also read that with SLI you can't have more than 2 monitors, so I removed the SLI connector, the option is still grayed out. Trying to run an update of the Nvidia driver now. There seems to be the option to do it under "additional drivers" and it seems to be working, I'll see how it goes after.

Edit: ok back to square one, two monitors working and I can login fine now. I'll stop touching stuff for tonight.

Edit2: Managed to get it working where two monitors act like I want (spanned but separate) and the other one has it's own X session. When I originally tried that it also screwed up the two other monitors making them act like one, so when I open something it would open half way between both and start bar and all was screwed up.

Now it works half decently. Normally I leave VNC open on the right monitor anyway, so the separate X session is not the end of the world I guess.

Only downside is I got an issue where it completely locked up and I got some error about not being able to open the folder. I copy and pasted it but it never made it through so I don't have the message anymore. I will post next time it happens. That will be a pretty major issue if it can't be fixed.

I'm just glad I managed to get back into my system, I really did not feel like having to reinstall everything, whether I chose to go back to windows or Linux.

 

[Nothinman]

Xinerama is an X extension, not an app. I'm not sure if you can even use it with the non-free nVidia drivers because it provides Xinerama data back to X apps that request it. You may need to try one of the free drivers to use pure Xinerama.

Installing the Nouveau driver should only be a pain if you do it from source. It's already packaged for Debian and it's probably already in your distro as well.

xserver-xorg-video-nouveau - X.Org X server -- Nouveau display driver

 

[Steltek]

Do you happen to be running a distro with a Gnome3-based desktop environment? I've seen Gnome2/MATE running three monitors using Xinerama, even with two different model nVidia cards installed, but Gnome3 supposedly won't work with three monitors (one of its still-existing bugs).

 

[Red Squirrel]

Using Xfce (xubuntu). I got it working by using a separate X session for the 3rd monitor, think that's the closest I'll get before I really muck something up. From what I gathered you cannot have a span between two monitors of two different video cards without jumping through some hoops. For what I tend to use that screen for it will work out ok I think. Hopefully this is an issue that gets sorted at some point, where it wont require complicated workarounds just to get 3 monitors to work.

Guess it does not help that everything is moving to phones and tablets, so multi monitor users are seen as a very small audience.

 

[Nothinman]

Using Xfce (xubuntu). I got it working by using a separate X session for the 3rd monitor, think that's the closest I'll get before I really muck something up. From what I gathered you cannot have a span between two monitors of two different video cards without jumping through some hoops. For what I tend to use that screen for it will work out ok I think. Hopefully this is an issue that gets sorted at some point, where it wont require complicated workarounds just to get 3 monitors to work.

Guess it does not help that everything is moving to phones and tablets, so multi monitor users are seen as a very small audience.

I wouldn't really consider switching to the free Nouveau or NV drivers as jumping through hoops and I would think it should only take like 15-30min to test. It does look like the non-free drivers only work well when all of the monitors are on a single card, so another option would be to buy a beefier card that can push 3 monitors.

People with >1 monitors have always been a niche, but I think you're right that the number is shrinking and people with >2 are going to be even more niche and less catered to.

 

[Red Squirrel]

Things were running fine for a while with the separate X session but suddenly now my other monitor has a bunch of blue squares in it and I can barely do anything in it. What a pain. You'd think Linux would be more ahead in this department. This is completely beta material right here.



Time to reboot... again. This is extremely unstable. Even Microsoft gets this right.

The issue with using Nouveau drivers as well is I was reading that you cannot game as it has no hardware acceleration. Not that I game a lot, but I still want to be able to at least game sometimes without having to constantly reboot my computer to go into windows. There are a few games like Minecraft that do run in Linux. Also if Nouveau happens to be what is used for the Live CD that wont work either. It causes the screens to flicker which is extremely annoying. Using the live CD install was the most terrible experience, and I don't even have Epilepsy.


Another thing I noticed is now every time I reboot my theme goes back to some black theme where the buttons have no labels. I don't know if I'm minimizing, closing, etc. I keep having to go change it back to a normal theme. I always have to fix the toolbars too as they tend to land on the wrong screens. What a mess this is. Adding a 3rd monitor should not be this complicated.

 

[mv2devnull]

I have two screens on one Nvidia card with Nvidia drivers and xfce and I see black theme after logging in on the first screen. Re-selecting my theme fixes that. I log in at most after each kernel update, so the issue is tolerable. Note: I specifically wanted two screens rather than single monitor-spanning (Twinview/Xinerama) screen.

Screens, Xinerama, and TwinView .. https://wiki.archlinux.org/index.php/Multihead has some reasonably looking text on the matter. Personally, I have not had the pleasure to test triple-headed gear.

Nividia did not have before Kepler generation any card that could run more than two monitors. That may have been one reason why their "TwinView" is limited to twin monitors.

 

[Red Squirrel]

Hmm well good to know I'm not the only one with that issue. Did you ever manage to find a fix? perhaps some kind of script that auto sets the theme? I tend to reboot a lot such as when I need to do something that requires windows. So I really want a flawless bootup.

Another issue I noticed as well is the task bars sometimes mess up, they appear wrong and I have to reconfigure them all. I even had one go on the wrong X session.

The separate X session thing is sorta growing on me, I can use that screen for stuff I always want up no matter what desktop I'm on. When I'm coding I tend to leave my server up so I can monitor the app. Sometimes I might just leave me email up, etc. So it's not that bad to not be able to move windows over.

Only thing that would be nice is if it would let me open a firefox session but Firefox seems to do this weird thing in certain situations where it wont let you open a second session, and that's one of the situations where it does it.

 

[Ken g6]

Did you ever find a fix for this? http://ask.slashdot.org/story/13/07...re-accelerated-multi-monitor-support-in-linux seems to have some ideas.

 

[Vic Vega]

...

 

[Piano Man]

Reminds me of when I tried to get 3 monitors up in CentOS 5.x with Radeon 75xx card. After giving up on all GUI tools, I spent two hellish days editing the xorg.conf until I finally got 3 monitors, but since 2 were 4:3 and one was 16:10, it was super messed up. I gave up.

I recently upgraded to CentOS 6.4 and on first boot, it saw all 3 monitors and applied the proper resolutions for everything. So there you have it

 

[Red Squirrel]

Hmm interesting, is it with more than one video card or just one that supports 3 monitors? I wonder if having 2 video cards is part of my issue. Went back to just 1 for now though with 1 monitor. Have not really been working on much except for troubleshooting lot of other issues.

I gave up on triple monitor for now as I'm still fighting with all my other issues like windows that half open and lock up forcing me to reboot, cursor getting stuck in hand icon, artifacts that show up on screen etc... Once I figure out all those issues I'll try to figure out triple monitors. I think what I'll end up doing for that is buying two new monitors that support HDMI, and get two raspberry PIs, and use synergy for the seamless mouse/keyboard interaction. Obviously wont be able to do anything like drag windows across though as it will be 3 separate machines but it's rare I have to do that anyway.

 

[ethebubbeth]

I had no problem doing triple monitor with a radeon 6950 or 7970 with the AMD binary driver. It automated the xinerama configuration in catalyst control center.

 

[Jodell88]

I stumbled upon this when I was looking at the nvidia forums. You need a kepler based card it seems to power more than two monitors. https://devtalk.nvidia.com/default/topic/570149/linux/multiple-more-than-2-monitor-support/

 

[Red Squirrel]

That is good to know they got it working. I'm having lot of issues with this PC and I suspect it's the card, so I will end up having to buy a new one anyway. If I can find a good deal on a rackmount nuclear reactor, I might get a Titan.

Though I hope this tech treats them as 4 monitors, and not as one, the post seems to suggest it treats as 1. That means stuff opens all over the place sometimes even half on one and half on the other.