4 Monitors With One Graphics Card And Standard Driver

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I’ve just test an ATI FirePro 2460 graphics card on CentOS 6.4. It connects 4 monitors. It worked with the standard radeon driver. I was able to arrange the monitors into my preferred configuration (as a square array, 1 upper left, 2 lower left, 3
lower right, 4
upper right) simply by clicking System -> Preferences -> Display, and then moving the four monitor images. This creates the file ~/.config/monitors.xml .

Moving windows among the monitors worked smoothly. I did not install the proprietary ATI driver; I don’t need any of its features beyond what the standard driver provides.

Some details:
Dell Optiplex 9010, Small Form Factor (SFF) case requires SFF cards.
CentOS 6.4 fully updated as of today.
2.6.32-358.2.1.el6.x86_64 kernel
xorg-x11-drv-ati 6.99.99 1.el6 x86_64
BIOS shows the board in slot 1 (the blue connector) as “VGA Compatible”
lspci shows
01:00.0 VGA compatible controller:
Advanced Micro Devices [AMD] nee ATI Cedar [FirePro 2460]
Kernel driver in use: radeon
No xorg.conf was created or required.
4 Dell 2007FP monitors, each at 1600×1200 connected via DVI.

I used to use Matrox M9140 cards, but that requires the Matrox proprietary driver which has not been updated for CentOS 6.4 as of today.

I also tested two other cards: ATI FirePro 2450 and NVidia Quadro NVS 420. For each of these cards, the BIOS shows the card in slot 1 as a PCI Bridge. lspci reports two identical video cards at 03:00.0 and 04:00.0. Though it’s easy to set up two screens properly, xinerama would probably be required in an xorg.conf to get all four screens working properly.

5 thoughts on - 4 Monitors With One Graphics Card And Standard Driver

  • Dale Dellutri wrote:

    Would you mind sending me your xorg.conf offlist? I *may* have found something in the one I’ve been handcrafting, but as my user is busy, I
    won’t be able to try it out for a while, and would love to see what you did.

    I’m still at the point of him having one monitor working fine, but the other comes up, not mirrored, but unreachable by keyboard or mouse. Looking at his old xorg.conf that worked with kmod-fglrx, and my own (an NVidia card) I realized they only have one Screen sectiuon, and a viewport on his (mine, of course, has twinview), so I’ve just edited his that way.


  • As I said, when I used the ATI FirePro 2460, there was NO xorg.conf created or required. I would have needed one for the ATI 2450 or the NVidia NVS 420, but I never tried to create one.

    I suggest that you restart the machine without X (in run level 3), then as root do:
    # X -configure which will write a new xorg.conf.new in the current directory.

    But are you sure the problem is in the xorg.conf? What does System ->
    Preferences -> Display show?

  • Dale Dellutri wrote:

    Tried that. It fails. Tried no xorg.conf, no X.

    That’s the fun one: it shows *one* monitor. I think I mentioned, xrandr shows 1, also. It *also* describes it as DisplayPort-0, though it doesn’t like me using DisplayPort-0 for output, and I can’t find what the output name *is*. But if I say xrandr –screen 1, it shows me DisplayPort-1.


  • Ok, I’m almost there. I found a typo in my xorg.conf – actually, I had copies one from someone out there that said it worked. Fixing that, in the ServerLayout section, and I’ve now got the two screens, side by side, and reachable. My two remaining problems: first, if I scroll around, it appears as though X thinks that the screen is bigger than the monitor, and it moves visible off the top of the monitor, leaving an L of black. The other is, if I log in as root, and try to use System->Display, it tells me RandR is disabled; meanwhile, in /var/log/Xorg.0.log, there are the two entries, one for each displayport, that say “ignore the following randr disabled message….


  • As it turns out, the ATI FirePro 2460 works, but it’s too slow with the standard radeon driver for our application.

    I tested an NVidia NVS 510 with both the standard nouveau driver, and the proprietary kmod-nvidia, nvidia-x11-drv rpms from elrepo. The two gave very similar quick response on our application, so we’ve decided to use the standard nouveau driver.

    Of all the cards I’ve tested, the 510 is the best.

    lspci shows
    01:00.0 VGA compatible controller:
    NVIDIA Corporation Device 0ffd (rev a1)

    The rest of the info is the same as shown above.