Multi-monitor on a single integrated graphics card?

[snarkyFish]

I'm working on setting up a system with a little mini-itx board. I need it to clone onto 2 screens, and this thing is encrusted with ports.. (svideo, dvi, hdmi, vga).. I assumed it would be easy.

When I plug in anything to this machine, a basic xorg will spit video out onto vga, hdmi and dvi just fine, but only one at a time. There seems to be some kind of hierarchy where one output disables another.

In the past, I've built this kind of thing with a custom written xorg.config but the systems always had multiple video cards. (one on board and one in a slot)

Would on board video capable of multi-monitor support show up in lspci as multiple devices? Or should I be trying to build an xorg that has monitors and screens that share a device section?

Here's my lspci:

00:00.0 Host bridge: nVidia Corporation Device 0a82 (rev b1)
00:00.1 RAM memory: nVidia Corporation Device 0a88 (rev b1)
00:03.0 ISA bridge: nVidia Corporation Device 0aad (rev b2)
00:03.1 RAM memory: nVidia Corporation Device 0aa4 (rev b1)
00:03.2 SMBus: nVidia Corporation Device 0aa2 (rev b1)
00:03.3 RAM memory: nVidia Corporation Device 0a89 (rev b1)
00:03.5 Co-processor: nVidia Corporation Device 0aa3 (rev b1)
00:04.0 USB Controller: nVidia Corporation Device 0aa5 (rev b1)
00:04.1 USB Controller: nVidia Corporation Device 0aa6 (rev b1)
00:06.0 USB Controller: nVidia Corporation Device 0aa7 (rev b1)
00:06.1 USB Controller: nVidia Corporation Device 0aa9 (rev b1)
00:08.0 Audio device: nVidia Corporation Device 0ac0 (rev b1)
00:09.0 PCI bridge: nVidia Corporation Device 0aab (rev b1)
00:0a.0 Ethernet controller: nVidia Corporation MCP79 Ethernet (rev b1)
00:0b.0 IDE interface: nVidia Corporation Device 0ab4 (rev b1)
00:0c.0 PCI bridge: nVidia Corporation Device 0ac4 (rev b1)
00:10.0 PCI bridge: nVidia Corporation Device 0aa0 (rev b1)
00:15.0 PCI bridge: nVidia Corporation Device 0ac6 (rev b1)
00:16.0 PCI bridge: nVidia Corporation Device 0ac7 (rev b1)
00:17.0 PCI bridge: nVidia Corporation Device 0ac7 (rev b1)
00:18.0 PCI bridge: nVidia Corporation Device 0ac7 (rev b1)
03:00.0 VGA compatible controller: nVidia Corporation Device 087d (rev b1)

As you can see, I'm pretty sure the only thing I've got is the last line.

The other symptom I've got is that xrandr -q does nothing but "Can't open display"

any ideas?

[krishna.murphy]

I suggest you look up the board and chipset; it sounds like there's only one "actual" video (e.g. video memory space) with multiple configurations - one at a time. Hopefully someone with more in-depth knowledge will enlighten us all.

Hope that helps!
Krishna

[kl522]

The other symptom I've got is that xrandr -q does nothing but "Can't open display"

any ideas?

Where did you issue the command from ? If you have X Windows running, and you open up a lxterminal ( or equivalent ), it should work. On my computer,

               $ echo $DISPLAY
                 :0

What's yours ?

[snarkyFish]

The system's at home and I'm at work so I can't hit it right now, but I ran it from .. whatever ctrl-F1 is called.. that terminal.
If I remember right, I did it both while X was running and while it wasn't, and got the same results.

I'll try echoing $DISPLAY with x running next and see what I get. Thanks!

[krishna.murphy]

The system's at home and I'm at work so I can't hit it right now, but I ran it from .. whatever ctrl-F1 is called.. that terminal.
If I remember right, I did it both while X was running and while it wasn't, and got the same results.

I'll try echoing $DISPLAY with x running next and see what I get. Thanks!

That terminal is actually not within X, AFAIK. You need to go to the GUI desktop and open LXterminal, (or even a root terminal from the Accessories menu) in order to get that command to work. Works fine for me, BTW.

Cheers!
Krishna
p.s. I've not had any luck getting to those "other" terminals since switching to version 6+. Something more than booting up must be needed for the key-binding to "take", at least on the systems I've tried it on. Maybe someone with more knowledge will take pity on me and address this, as I have asked before and got no joy.

[snarkyFish]

Ok, I fired up a fresh copy of knoppix 6.2.1 on this box, opened up a terminal inside x and got xrandr -q to work.. (thanks! /forehead slap)

So, with both VGA and Hdmi monitors plugged in, (and it only displaying a signal on vga) this is what i've got:

Screen 0: minimum 1024 x 768, current 1024 x 768, maximum 1024 x 768
default connected 1024x768+0+0 0mm x 0mm
   1024x768       76.0*

Should I see both monitors there, even though one isn't correctly configged in xorg.conf? (I have yet to find a configuration that works at all)

After that, I pulled the vga, rebooted, the system came up displaying over the hdmi port on that monitor, and xrandr -q reported the exact same thing above.


So, questions:

Is there a way to get knoppix to correctly identify these monitors native resolutions and such? or do I have to pull the specs on them and build that stuff myself?

If xrandr only ever sees Screen 0, and my lspci above only displays one video card, am I screwed for getting a dual monitor setup on this system short of installing another video card? This hardware's all brand new.. I can't believe it won't do dual monitors.

I've tried everything, now I'm mostly looking for whether it's possible or not, so i can send this hardware back and move on if I have to.

Thanks!

[krishna.murphy]

I'd fall back on looking up the board/chipset specs - the mfgr. should say what it'll do. Continuing to poke around and "see what you can do" strikes me as less than promising.

Cheers!
Krishna

[snarkyFish]

Man, that's pretty much what I needed to do. I went back to the drawing board.. dug up the manual on the board /chipset.. found some linux drivers, did some installing / updating, and got it recognizing all of its wonderful nvidia capabilities..

Then I dug up an nvidia manual for configuring TwinView in xorg, and it worked surprisingly easily. I was just getting hung up on failing updates and bad drivers before.

So, to answer my own questions for future googlers: Yes one 'device' in xorg can totally drive multiple monitors, but you need the right nvidia driver and nvidia's twinview config to make it happen. Also, you should RTFM early and often... ; )

Thanks for the help everyone!