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Ask Slashdot: Hardware Accelerated Multi-Monitor Support In Linux? 278

An anonymous reader writes "I'm an Engineer with a need for 3 large monitors on the one PC. I want to run them as 'one big desktop' so I can drag windows around between all three monitors (Windows XP style). I run Debian and an nVidia NVS450. Currently I have been able to do what I want by using Xinerama which is painfully slow (think 1990s), or using TwinView which is hardware accelerated but only supports 2 monitors. I can live without 3D performance, but I need a hardware accelerated 2D desktop at the minimum. What are my options? I will happily give up running X and run something else if I need to (although I would like to keep using Xfce — but am open to anything). I am getting so desperate that I am starting to think of running Windows on my box, but that would be painful in so many other ways given my work environment revolves around the Linux toolset."
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Ask Slashdot: Hardware Accelerated Multi-Monitor Support In Linux?

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  • by Anonymous Coward on Saturday July 27, 2013 @11:27AM (#44399663)

    A pair of nvidia 9800gtx cards gives me quad DVI on which I run three monitors. The option you are seeking is basemosaic. I don't have the config in front of me or I would include it.

    • by amginenigma ( 1495491 ) on Saturday July 27, 2013 @11:35AM (#44399721)
      I also do not have the config in front of me, but mosaic is what you are looking for in your xconfig. Bit of googling ( on that should point you in the right direction. And yes once configured it's as 'easy as Windowz...'
      • What specifically did you google? How long did it take you to find that?
    • by Mad Merlin ( 837387 ) on Saturday July 27, 2013 @01:14PM (#44400471) Homepage

      That's not necessary anymore. Kepler based cards (GTX 600 and 700) support up to 4 monitors. I'm posting from 3 monitors connected to a GTX 670.

    • ditto but different cards. I didn't even think this was an issue.

    • by yhetti ( 57297 ) <yhetti@sh e v> on Saturday July 27, 2013 @04:56PM (#44401909)

      I can confirm that BaseMosaic on an NVS450 works under LMDE (Debian Testing) using:

      Section "Screen"
              Identifier "Screen0"
              Device "Device0"
              Monitor "Monitor0"
              DefaultDepth 24
              Option "BaseMosaic" "True"
              Option "MetaModes" "GPU-1.DFP-0: 1680x1050+0+0, GPU-0.DFP-1: 1680x1050+3360+0, GPU-0.DFP-0: 1680x1050+1680+0; GPU-1.DFP-0: NULL, GPU-0.DFP-1: NULL, GPU-0.DFP-0: 1680x1050"
              SubSection "Display"
                      Depth 24

  • by tramp ( 68773 ) on Saturday July 27, 2013 @11:30AM (#44399689)
    arandr is a standard package in Debian and can be used with Xfce too. []
    • Re: (Score:3, Informative)

      by Anonymous Coward

      I use xrandr with Arch and Xfce and it works fine:, so I suspect arandr for Debian will achieve the same results. How did this get past the /. moderators?

      • I use xrandr with Windowmaker. Works fine for me. I rotate one of my monitors so I can view long listings and docs. Love the screen real estate!
  • by Anonymous Coward on Saturday July 27, 2013 @11:32AM (#44399703)

    This works out-of-the-box with any number of monitors (well, as many as the number of CRTCs provided by your GPU) for ATi Radeons (both free and proprietary drivers) and Intel (free drivers).

    Now, embedded Intel usually only has two CRTCs, but the newer Radeons have at least three, up to six.

    You just need to configure the viewports using your preferred desktop environment or directly using xrandr or the config.

    • Works out of the box for me too on an NVidia based card running dual screens.

    • I have a Radeon 7850 with 2 dual link DVI ports and a displayport. It won't allow more than one DVI output to run dual-link resolutions. I doubt *three* monitors like this guys asks for will work if two won't even work.... Mind you, his current Nvidia board will do it just fine, but ATI is severly limited when it comes to proper resolutions on non-displayport screens.
  • by Coeurderoy ( 717228 ) on Saturday July 27, 2013 @11:34AM (#44399719)

    You might be using the open source driver and not the nvidia driver.
    We use Two GTX220 or GT650 and plug three or four terminals withouth any hassle, but we do use the proprietary nvidia driver.

    And the result is quite fast (we typically test our games on two full HD monitors while running our development tools in one or two others.

    I suspect the NVS450 is also more expensive than our setup :-)

    BTW we use either debian or ubuntu depending of the whim of each developper.

    • Games development on linux? Do you work for Valve?

      • CnlPepper, yes real Game development. Especially when Leadwerks (Kickstarter) comes out, which allows you to make AAA quality Games for Linux IN Linux. Also Unity3D can export to Linux. Ogre (Torchlight) is OK if you want something free.

    • by houghi ( 78078 )

      he official software also comes with nvidia-xconfig for the initial config, nvidia-settings to be run as root for the settings and nvidia-smi for the CLI part.
      I use openSUSE and after adding the NVidia repo, I do the following:
      1) Close X
      2) As root, run nvidia-xconfig
      3) Log back in as standard user
      4) Open a terminal, su to root and run nvidia-settings
      5) Configure anything as I desire
      6) Restart X

      I have a GeForce GT 520 (1GB) and a GeForce 8400GS (0.5GB) with 2x1920x1200 and 2x1920x1080. Both GPU's run at belo

    • Unfortunately, while the NVS series bare the Quadro branding, NVidia does not support the professional/scientific feature sets on those chips. So, features like the unified back buffer, etc. are not available. Essentially, the NVS450 is a card with two GeForce 8400 chips and a PCI-E to PCI-E bridge. It's kinda lame.

      NVidia marketing material suggests that the NVS line is intended for business users who need to support many displays without any advanced rendering.

      While you're right, I imagine the NVS450 costs

  • Try the README.txt

  • []
    with the nvidia drivers version 304 or newer.
    Have 2 machines each with one of these cards. drives 3 monitors one of which is even in portrait mode.

  • After weeks of trying to get AMD/Gigabyte motherboard and video card to drive 4 displays on linux, it just didn't work.
    Tried 3 different distros, god knows how many xorg confs and driver combinations.
    In the end I broke down and bought a NVIDIA GTX 760 for the following reasons.
    *Drive 4 displays in Linux no problem with HW Acceleration.
    *4 displays can be driven at 1920x1080.
    *OpenCV has Cuda support , nothing for OpenCL yet.
    *Openscenegraph has Cuda library, nothing for OpenCL yet.
    *The Nvidia settings manager

    • by sl149q ( 1537343 )

      I tried to upgrade to Linux Mint 14 in January using an Radeon Card. Could not get multi-monitor to work.

      Ended up back with Nvidia and it works. Four monitors, just use the nvidia drivers and nvidia settings applet.

      I have subsequently upgraded the MB to a Z87 based system so am now trying to attach two monitors to the MB video as well. For those I want to have a second keyboard / mouse and run a different window manager.

  • I just used (Score:5, Informative)

    by mocm ( 141920 ) on Saturday July 27, 2013 @11:51AM (#44399863)

    the nvidia-settings tool to set up 4 monitors on my GTX670, there is no problem with speed and I get hw accelerated 3d on every screen. The driver is NVidia's 310.19. I used the TwinView Option on the Layout selection screen and could put the monitors into the wanted configuration with the GUI. I can move windows between the monitors and xfce gives me panels on the separate monitors.
    The screen section in the xorg.conf looks like this:
    Section "Screen"
            Identifier "Screen0"
            Device "Device0"
            Monitor "Monitor0"
            DefaultDepth 24
            Option "TwinView" "0"
            Option "Stereo" "0"
            Option "nvidiaXineramaInfoOrder" "DFP-0"
            Option "metamodes" "DFP-0: nvidia-auto-select +0+0, DFP-1: 1920x1200 +1920+1080, DFP-3: nvidia-auto-select +1920+0, DFP-4: nvidia-auto-select +0+1080; DFP-1: 1920x1200 +0+0; DFP-1: 1920x1200 +0+0"
            SubSection "Display"
                    Depth 24

    and the server layout:

    Section "ServerLayout"
            Identifier "Layout0"
            Screen 0 "Screen0" 0 0
            InputDevice "Keyboard0" "CoreKeyboard"
            InputDevice "Mouse0" "CorePointer"
            Option "Xinerama" "0"

  • by Anonymous Coward

    My Ubuntu workstation has an HD 7950, using proprietary drivers installed from the Settings menu. Currently running three 1080p monitors, two of which are rotated portrait mode. Any HD 7xxx series card is supposed to be able to run up to six monitors, though you usually only get four outputs (six requires monitors that support DisplayPort daisy-chaining).

    Oh, and I occasionally play DotA 2 on Steam for Linux on this as well. Apart from trying to start on the wrong monitor, it works very well.

  • I feel like I'm missing something; this was dirt-simple for me.

    I used to have a computer with an Nvidia card. I had Ubuntu on it. I had the Nvidia drivers installed. I had the nvidia-settings utility installed (which for some reason wasn't included by default). I plugged in the extra monitors. I opened nvidia-settings. I clicked "Detect Monitors". I enabled them. Suddenly I had several monitors without having to touch a single config file.

  • Until a few months ago at work I was running triple-head on an Ubuntu 10.04 LTS desktop with an ATI Radeon something-or-other card. Hardware acceleration was supported. The third head was analog, but AFAIK that was just a limitation of the sub-$150 graphics card I was using (only 2 digital ports), not something inherent in X or the drivers. I was surprised to discover that triple head was even possible with an inexpensive card.

    I did need to install a beta version of the proprietary drivers, and IIRC it took

  • I've got four monitors (one is 2560x1600) on a single Radeon HD 6870 and it does everything you want. Running Fedora 17 with the proprietary ATI drivers, FVWM2, with a single desktop and 3D hardware acceleration. I tested F19 with Gnome and free drivers too.

  • But if more than 2 monitors is the issue, why not get 2 of the latest really big/high res ones and stop whining?

    • Yeah, really. If he needs 3 different desktops, you can always split the monitors in multiple parts using virtual servers, IIRC. For some things I find that's better. Especially with these long 16:10 monitors where they're generally too long for things like reading web pages.

  • The biggest issue is that everything but displayport sucks donkeyballs. So get a firepro card from AMD with 6 display ports and run it with the linux native driver. Works fine for me. I use XFCE myself with such a setup with 3x 2560x1600. I have tried to do it with HDMI and such but run into all kinds of weird issues where displayport just works right every time.

    I am to lazy to search for mine but it isn't even a 3D card so it was pretty cheap and fits in any PC (no extra power needed). If you want 3D you

    • I use XFCE myself with such a setup with 3x 2560x1600.

      Holy crap you have a big desk!

      Out of interest since you mention anything but DP sucking, do you use the cheapie no-name IPS monitors which require a powered DP to dual-lnik DVI converter or do you use more expensive ones which take in DP directly?

      • The monitors are on their side, so they are really 1600x2560. On their side they are 45cm each. It gives me a desktop where I can code long pages in the center screen and have debug and info to the left and right at eye level and info displays I need only occasionally at the top and bottom.

        I have several generations of Dell monitors, U3011 and U3014. They have direct displayport. I have tried it with converter cables and it is a nightmare with having to edit x config files. The moment I switched over to pu

        • The monitors are on their side, so they are really 1600x2560.

          Interesting setup. I should try it some time.

          I have several generations of Dell monitors, U3011 and U3014. They have direct displayport. I have tried it with converter cables and it is a nightmare with having to edit x config files. The moment I switched over to pure display port, everything just worked.

          Converter from what to what? I was specifically wondering about DP to DVI, since the DVI only monitors are substantially cheaper than the Dell on

  • This is worth a read: []

    It seems nVidia restrict you to two monitors on Linux whereas you can happily use three on Windows. I have no idea why other than that they are clearly bastards.

    • by sl149q ( 1537343 )

      I better unplug two of my four monitors really quickly! Must just be my imagination that I can see windows and drag things to them...

  • The posters question is answered the exact same way on MS Windows or linux, hardware that supports the number of screens desired and a driver downloaded from the hardware vendor. Whether it's two low end cards to do four screens or it's one relatively high end (as in more than $100 instead of dirt cheap) card that's what will do the trick. I've done it with both ways with no problems on linux and only a few problems on MS Windows with two cards (limited options for cloned screens, so normally not a big de
  • At work I have a multimonitor setup running Debian 7 / Gnome 3. Works perfectly. I'm using an ATi graphics card (can't remember the model) and the proprietary drivers, it's accelerated and works very well. Setup was very straightforward - run the setup for the ATi drivers, then select in the GUI how you want your displays.

  • I am not happy if I do not have at least 6, better 9 virtual desktops with quick switching. The FVWM pager gives you customizable edge-scroll, easy dragging of windows between desktops, multi-desktop spanning windows, etc. One reason Linux does not have multi-monitor out of the box is that it is almost never needed, different from Windows, where one cluttered desktop is the norm.

    • Huh?

      Linux supports multimonitor out of the box very well, and I say this as a die-hard FVWM user. This small-screened laptop has 30 (3x10) panels in the pager btw.

      Problem with FVWM though is it doesn't respond to xrandr events which means that when you change the monitor setup, none of the windows line up any more, if you use the pager in large-virtual-desktop mode as opposed to disjoint desktop mode.

      Still, it works fine with xinerama geometries.

  • by hawkeyeMI ( 412577 ) <brock@brocktic[ ]om ['e.c' in gap]> on Saturday July 27, 2013 @01:12PM (#44400451) Homepage
    Just get a Radeon Eyefinity model, with 4-6 mini-DisplayPorts on it. Works great. Been running like this in Debian with 4 monitors for years now using fglrx drivers.
  • 3 head ati cards are easy to come by.

    In 2009, we did 24 displays on on PC. Each 3x2 quadrant is randr based. That is what you want.


  • I've been running a three-monitor desktop for many years, and I've had to use Xinerama to get it to work. This results in some serious performance issues occasionally (I think triggered by Adobe Flash, not surprisingly) where the whole system becomes mostly non-responsive for a while. The right way of doing it is to use xrandr to configure the displays into a single logical screen. That would work great if I had a video card that could drive all three monitors. Unfortunately, I have two separate video c

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