Arch Linux

clutch

Member

Registered: 2010-05-01

Posts: 48

[SOLVED]triple head woes

Hey, trying desperately to get all three of my monitors working, with limited success.  Here's where I'm at so far:

Three seperate X screens sort of works.  This is not exactly what I want to do though.  It seems awkward having three seperate instances of DWM running, it doesn't allow me to use the usual mod + >/< to switch focus, and not being able to move windows from one screen to the next is a little annoying. 

I tried using two of them with Twinview, and the third as a seperate X screen, but doing this causes twinview to decide that the first two monitors are one big one and stretch things across them.  Wouldn't be that big of a deal in a floating wm (albeit obnoxious), but it makes tiling pretty much unusable.  I was also half asleep when I was messing around with this and can't figure out how I even managed to get the third monitor working at all with twinview running, and have been so far unable to replicate it.  Not that it matters, because it wasn't really usable anyway.

The trouble I'm having is that there is a lot of outdated information floating around and I'm not sure what to do.  The wiki Xorg page has a section on Multiple/Dual Head, but the example xorg.conf given is specific to running 2 displays, not 3.  If anyone could point me in the right direction or show me how they got triple-head working on two nvidia cards it would be greatly appreciated.

Running 2 displays off of a GTX460, the third one is from a 7200GS.  I know they both work.  Using the Nvidia driver because the kind people over in #nouveau seemed pretty sure that there wasn't any way to get a single x session to span three displays using nouveau.

Last edited by clutch (2011-01-15 19:05:23)

BurntSushi

Member

From: Massachusetts

Registered: 2009-06-28

Posts: 362

Website

Re: [SOLVED]triple head woes

I personally don't have a triple head setup (although, I'd like to, some day), but one way to do it might be using a Matrox TripleHead2Go. (Or a DualHead2Go, since you have two cards.)

You should have much better luck at the nVidia forums: http://www.nvnews.net/vbulletin/forumdisplay.php?f=14 (Search first! Other people have tried this.)

I tried using two of them with Twinview, and the third as a seperate X screen, but doing this causes twinview to decide that the first two monitors are one big one and stretch things across them.  Wouldn't be that big of a deal in a floating wm (albeit obnoxious), but it makes tiling pretty much unusable.

TwinView is supposed to make two monitors look like "one." It's actually up to the window manager to discern their difference. I don't know anything about DWM, but you might want to look and see if there is support for Xinerama. (Most window managers today support xinerama, and therefore, TwinView... Like Openbox and Awesome, I think.)

---

Education is favorable to liberty. Freedom can exist only in a society of knowledge. Without learning, men are incapable of knowing their rights, and where learning is confined to a few people, liberty can be neither equal nor universal.

Tu ne cede malis sed contra audentior ito

clutch

Member

Registered: 2010-05-01

Posts: 48

Re: [SOLVED]triple head woes

I tried using two of them with Twinview, and the third as a seperate X screen, but doing this causes twinview to decide that the first two monitors are one big one and stretch things across them.  Wouldn't be that big of a deal in a floating wm (albeit obnoxious), but it makes tiling pretty much unusable.

TwinView is supposed to make two monitors look like "one." It's actually up to the window manager to discern their difference. I don't know anything about DWM, but you might want to look and see if there is support for Xinerama. (Most window managers today support xinerama, and therefore, TwinView... Like Openbox and Awesome, I think.)

I'll try those forums as well and see if I come up with anything.  I've read accounts of it being done, but they were all 3+ years old which might as well be 30 years as far as these things are concerned.  I'd just as soon run 3 seperate screens as buy a matrox - they're a little expensive for something that (imo) should just work to begin with using two GPUs.  I can see the appeal and cost-effectiveness if you're trying to run something like 6 displays off of 2 cards though I suppose.

I know DWM is Xinerama-aware since 5.8 I think, and Twinview works perfectly for it until you add in a seperate x screen.  From what I've read this is an X issue rather than an Nvidia issue and there are patches for some lib or other that will allow it to work.  But, again, the only thing I found was posted somewhere back in 07 and surely isn't relevant anymore, and it allegedly only worked for three monitors of the same size.  I'm using a 1600x900 flanked by a pair of 1280x1024 displays.

Last edited by clutch (2011-01-15 06:49:26)

jasonwryan

Anarchist

From: .nz

Registered: 2009-05-09

Posts: 30,424

Website

Re: [SOLVED]triple head woes

Is this relevant?
https://bbs.archlinux.org/viewtopic.php?id=111017

---

Arch + dwm   •   Mercurial repos  •   Surfraw

Registered Linux User #482438

clutch

Member

Registered: 2010-05-01

Posts: 48

Re: [SOLVED]triple head woes

Is this relevant?
https://bbs.archlinux.org/viewtopic.php?id=111017

Wow, sorry, not sure how I missed that, hahaha.

Will start over from scratch and post results in the AM.

BurntSushi

Member

From: Massachusetts

Registered: 2009-06-28

Posts: 362

Website

Re: [SOLVED]triple head woes

Is this relevant?
https://bbs.archlinux.org/viewtopic.php?id=111017

Wow, sorry, not sure how I missed that, hahaha.

Will start over from scratch and post results in the AM.

Please do. I'm very interested in how it goes! :-)

Last edited by BurntSushi (2011-01-15 15:30:37)

---

Education is favorable to liberty. Freedom can exist only in a society of knowledge. Without learning, men are incapable of knowing their rights, and where learning is confined to a few people, liberty can be neither equal nor universal.

Tu ne cede malis sed contra audentior ito

clutch

Member

Registered: 2010-05-01

Posts: 48

Re: [SOLVED]triple head woes

Ok, finally got it.  I have no idea what I was doing wrong.  I was setting up my 10-monitor.conf the same way as it was in that other thread yesterday and nothing was working.  Deleted everything and started over from scratch today and it all works exactly how I wanted it to, so I'm just going to call it good and not mess with it anymore.

My 10-Monitor.conf for any future visitors that are interested:

Section "ServerLayout"
    Identifier        "Layout0"
    Screen          0 "Screen0" 0 0
    Screen          1 "Screen1" RightOf "Screen0"
    Screen          2 "Screen2" RightOf "Screen1"
    InputDevice     "Keyboard0" "CoreKeyboard"
    InputDevice     "Mouse0"   "CorePointer"
    Option          "Xinerama" "1"
EndSection

Section "InputDevice"
    Identifier "Mouse0"
    Driver "mouse"
    Option "Protocol" "auto"
    Option "Device" "/dev/psaux"
    Option "Emulate3Buttons" "no"
    Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    Identifier "Keyboard0"
    Driver "kbd"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "ViewSonic VG171b"
    HorizSync       30.0 - 82.0
    VertRefresh     50.0 - 75.0
    Option         "DPMS"
EndSection

Section "Monitor"
    Identifier     "Monitor1"
    VendorName     "Unknown"
    ModelName      "DELL ST2010"
    HorizSync       30.0 - 83.0
    VertRefresh     56.0 - 76.0
    Option         "DPMS"
EndSection

Section "Monitor"
    Identifier     "Monitor2"
    VendorName     "Unknown"
    ModelName      "EMA e17t4"
    HorizSync       30.0 - 80.0
    VertRefresh     56.0 - 76.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX 460"
    BusID          "PCI:1:0:0"
    Screen          0
EndSection

Section "Device"
    Identifier     "Device1"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX 460"
    BusID          "PCI:1:0:0"
    Screen          1
EndSection

Section "Device"
    Identifier     "Device2"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 7300 SE/7200 GS"
    BusID          "PCI:2:0:0"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "metamodes" "1280x1024_75 +0+0"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"
    Identifier     "Screen1"
    Device         "Device1"
    Monitor        "Monitor1"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "metamodes" "1600x900_75 +0+0; nvidia-auto-select +0+0"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"
    Identifier     "Screen2"
    Device         "Device2"
    Monitor        "Monitor2"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "metamodes" "1280x1024_75; nvidia-auto-select +0+0"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Its a little different from the one in the other guy's thread, since my setup is different.  Startx wouldn't work without the inputdevice stuff, so I just left it there.  Judging from the log it has something to do with my 10-quirks.conf, but I'm not going to fsck with it when it works just fine.

Moving windows over to the third display (Screen2, the one that is on a seperate GPU) is a little bit clunky, but its easily tolerable.

I've got to say, this is probably my only gripe with Linux as compared to Windows.  I had the same setup working flawlessly on my Windows 7 gaming partition in about 5 minutes flat, including a reboot.

Thanks for your help guys.

Last edited by clutch (2011-01-15 19:09:01)