Ken--
Luke has summed it up, there are many ways to do it, and no one will claim
to have THE solution. We do multiple monitor desktops in quite a few
different ways, I'll give you a run down of hardware, and if you want more
details and/or config files, I can provide them
Original:
ATI Rage vintage cards, 1-AGP + n-PCI to give n+1 monitors.
We used this up to 4, and it works great, although not the most high
performance solution. Finding PCI cards of this vintage may be an issue, but
we had a bunch around. X supports them.
Second:
Radeon 7500 (PCI or AGP) with dual output (DVI + VGA).
These work great for us, X for SL supports them easily out of the box. I had
trouble getting both to work simultaneously, the second ATI card does not
initialize correctly (known bug), but I think there may be a work around for
that if you need > 2 monitors with these. These are vintage though, there is
probably a newer solution.
Third:
Matrox G450 AGP
Works OK, using Matrox drivers. Must recompile with kernel updates.
Fourth:
Matrox P650 AGP Triple head mode. 2 DVI outputs, one with a fork to 2 VGA.
Using Matrox driver, I've never been terrible happy with these, there are
"artifacts" left on the screen, little bits of one window border left over
when one window is moved over another. Some hard lockups observed as well,
but I can't pin it down.
Fifth:
Matrox G550 PCIe
Matrox Driver. These work OK, although could not get more than one to work
at a time, we needed more than one for more than 2 monitors. Worked OK with
an ATI Radeon 7500.
Sixth:
PNY nVidia Quadro4 400 NVS PCI
This was the latest solution, and I am very happy with it. Using nVidia's
driver (compiled before I realized it was in contrib) we can get full
acceleration on all 4 heads. On 2 of our setups we have 2 of these driving 8
19" LCD's at 1280x1024. THAT is a desktop!
There are all sorts of minor issues when using more than one card,
initialization etc, but if you only require 2 monitors, that should be
trivial. As I said in the previous email, I'd rather have more than one 4x3
aspect ratio monitor than a widescreen, but that is just a personal
preference.
Hope that helps
Chris
--
Chris Payne ISAC Operations Controls System Manager
"Relax Snap, this is particle physics, not rocket science."
On Wed, Aug 02, 2006 at 09:58:31AM -0400, Luke Scharf wrote:
> Date: Wed, 02 Aug 2006 09:58:31 -0400
> From: Luke Scharf <[log in to unmask]>
> User-Agent: Thunderbird 1.5.0.5 (Macintosh/20060719)
> To: Ken Teh <[log in to unmask]>
> CC: Chris Payne <[log in to unmask]>, [log in to unmask]
> Subject: Re: SL4x wide LCD support
> In-Reply-To: <[log in to unmask]>
>
> Ken Teh wrote:
> >Dual monitors seemed the way to go but I did not get a definitive
> >recipe for this. Some suggested 2 video cards; some, a video card
> >with 2 ports. The video card with 2 ports was conceptually
> >straightforward but expensive. I'm confused by 2 video cards---not
> >sure how the video space is consolidated.
> You didn't get a recipe for it, because any of the alternatives that you
> suggest will work fine for regular desktop usage. I'm guessing that
> nobody wants to tell you "Nein! Do it may way!", because what makes
> sense depends on your resources (cash, or interesting hardware in the
> junk pile, time), and the application that you hope to run. That's what
> we get for being on a listserv full of professionals. :-)
>
> And any confusion that you may have about how the space is allocated
> between the two monitors probably stems from the fact that the behavior
> is configurable, and there are enough options to do it however you think
> it should be done. Here are some points to help you follow discussions
> on it:
>
> 1. In a dual video card system, the cards really are independent. If
> your OS doesn't support multiple video cards, the BIOS will pick
> one card and display its stuff there. The OS's video driver
> usually will choose the same video card and display on only that
> monitor. Also, the BIOS will usually fail to start the secondary
> card's initialization process, so the card will generate
> no-signal, and the monitor that is attached to it will just
> sort-of blink the "I'm saving you electricity!" message. Of
> course, there are odd BIOSs and odd video drivers that will break
> these rules in some situations.
> 2. A card with dual outputs will usually display the same image on
> both output-ports, but, when initialized by a proper driver (say
> NVidia's proprietary accelerated driver (for NVidia cards,
> obviously)), then it will act like to video cards. Some newer
> laptops have this behavior for the LCD and the VGA output - it'll
> behave like the old-fashioned toggle-switch, or you can run a
> dual-head setup if you want.
> 3. One way that you can run a multi-monitor system is called
> "Xinerama". In this mode, the applications on the system think
> you have one big, wide (or tall, depending on how you configure
> it) screen. You can drag windows from one screen to the other, or
> place one so that it spans most monitors. The disadvantage of
> this setup is that the monitors and cards need to have similar
> capabilities. I believe that it has been resolved, but back in
> 1998, displaying video and doing 3D on a Xinerama setup was a bit
> dodgy -- things are much better now, especially with Xorg.
> Xinerama is the behavior that most people expect, and, in my
> experience, the most popular way to run multiple monitors.
> 4. Another way that you can run a multi-monitor screen is using
> X-Windows own multi-monitor protocol. You can't move windows from
> one screen to the other easily (or at all?), but you can specify
> which screen the window appears on by changing your $DISPLAY
> variable. The advantage of this is that the screens can be
> configured more independently - IIRC, you can run one screen with
> 3D acceleration and the other without?
>
> I hope this helps,
> -Luke
>
> --
> Luke Scharf
> Virginia Tech Unix Administration Services
> Terascale Computing Facility
>
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