2x ATI 5670 & 3 Monitors - How?

[gtrawoger]

Hi All,

I have done a bit of googling on this, but haven't found a solution yet (just dissatisfied 'customers'). What I would like to be able to do is run 3 monitors on 2 ATI 5670's.

So far I got 2 of the monitors working on one card with fglrx, but the driver doesn't seem to find the other card (just says unknown on the 3rd monitor.)

Is there some switch I missed? Or do I need to go over to the open source driver?

Anyone got experience with a 3 Monitor/2 ATI card setup?

[farofeiro]

Have you already managed to have X working with each monitor at a single time?

I know how to have triple head using 2 ATI cards using xinerama (no direct rendering), but I guess eyefinity enabled cards can do triple head with direct rendering. At least, that's what I see in this video: http://www.youtube.com/watch?v=N6Vf8R_gOec.

[gtrawoger]

Ok. Figured it out. After a quick 'sudo aticonfig --adapter=all --initial' I got the second card working.

The only thing is that compiz is turned off because of Xinerama (needed to drag across all three sceens). The 2D is somewhat choppy, but it's working.

[bridgman]

There used to be an aticonfig option (-all ?) that was required to initialize multiple adapters. Not sure if it is still required but check the end of aticonfig --help output.

Many Evergreen cards will drive 3 displays off a single GPU if you use a DP-to-whatever adapter for the third display.

EDIT - looks like we crossed in the mail, never mind - glad you got it running.

[gtrawoger]

Thanks bridgman.

Yeah, it seems to run 3 displays now, but the latest is that it crashes X as soon as I open a window and try to click on anything.

Not sure what is going on.

[gtrawoger]

Ok, turning OFF xinerama seems to stop the madness. I tried opening ccc and everytime I HOVER over the window, X would crash.

[bridgman]

Were those crashes before you turned off Xinerama or after ?

[gtrawoger]

Were those crashes before you turned off Xinerama or after ?

Before. After I turned it off, everything was working fine. Found a thread that mentioned that Xinerama with more than 3 monitors will crash X (with nvidia as well).

I now purged the fglrx driver and switched back to the open source driver. Found a xorg.conf online that someone got working with XRandR and 3 monitors. Just changed it to fit my setup and I am up and running with 3 monitors and the open source driver.

[gtrawoger]

bridgman, here is the link to the thread: http://ubuntuforums.org/showthread.php?t=1489377

If you go down a few posts, you'll see that there are a few that have issues with Xinerama.

I am now realizing (never had a 3 monitor setup before) that Xinerama is a pile of poo. Not even compiz can be enabled when you have more than 2 monitors (neither ATI, nor nvidia).

Hopefully Wayland will give Linux the edge it really needs. X is antiquated.

[bridgman]

Thanks. BTW if you run all 3 displays on one card you should be able to get Compiz etc..

I haven't tried it myself but it should all fit together pretty well. The Eyefinity GPUs let you take X up to 6 displays (on a single GPU, assuming the card has enough of the right connectors) without having to deal with multi-card issues.