Quad monitor configuration using xinerama

Uli Sing · Apprentice Joined: 03 May 2010 Posts: 187 Location: MUC

There was a time when the gods of the endless linux universe decided to banish a working, well-engineered system giving us an unfinished and deficient replacement instead. They called it randr and had no ear for the complaints of billions of long-standig content xinerama users.

Okay, maybe I overshoot the mark but the fact is: randr is in some ways less comfortable and still lacks in multi-card support.

The goal: Operate four monitors using two dual head ATI graphic cards
The clue: xf86-video-ati-6.9 is AFAIK the last working driver version
The hardware: 2x ATI FireMV 2200 PCIe 16x, an appropriate mainbord and of course four monitors

What we cannot use:
/etc/portage/package.mask

kingfame_147 · Apprentice Joined: 11 Oct 2008 Posts: 157

ATI Eyefinity cards are cheap and you can easly setup 4 monitors with them using randr :)

Uli Sing · Apprentice Joined: 03 May 2010 Posts: 187 Location: MUC

randr is giving a bicycle frame to your kid telling wheels and saddle coming next year.

BitJam · Posted: Sat Feb 26, 2011 7:25 pm Post subject:

norg · Posted: Sat Feb 26, 2011 9:53 pm Post subject:

I use ATI Eyefinity with three LCDs HP ZR24W on a PowerColor Radeon HD 5770 Eyefinity 5 Edition. It's working really good. There are just some issues with applications in fullscreen, some are working, some are cloning the screen on every LCD and the Triple-Head setup is broken. But this may be a issue with this applications. Configuration is quite simple and i'm working with awesome WindowManager. I used i3 before but the support wasn't perfect. I also have the problem, that sometimes the cursor gets broken but that's no big deal. And the tearing and no vsync on videos is nothing new

All in all i'm quite happy with it and i prefer this setup instead of xinerama and two graphic cards, although NVIDIA Twinview Support for more then two LCDs would be nice.

I'm using x11-drivers/ati-drivers 10.12 and x11-base/xorg-server 1.9.4 right now.

BitJam · Posted: Sat Feb 26, 2011 10:06 pm Post subject:

For me, tearing/lack-of-vsync is a show stopper. I was hoping ATI was doing a better job at addressing this issue than Nvidia.

norg · Posted: Sat Feb 26, 2011 10:34 pm Post subject:

Well in games i have no tearing, so vsync is working it's just with videos and should be fixed with 11.2 AFAIR. I also had tearing/vsync issues with nvidia.

kingfame_147 · Apprentice Joined: 11 Oct 2008 Posts: 157

I don't see any kind of tearing or problems with videos.
But I don't use the closed source drivers. The opensource radeon driver is working great and therefore I don't see why I should closed source software.

For what reason do you need vsync at video playback?! I don't know if that is working with the radeon driver, but why should I care about that? Vsync is on by default at the radeon driver, but I can't seen any difference when turning it off.

norg · Posted: Sun Feb 27, 2011 3:25 pm Post subject:

I needed Eyefinity support, so the closed source driver was the only chance. Besides, it has better 3D support. Vsync and Tearing offen occurs with Multi-Head setups.

kingfame_147 · Apprentice Joined: 11 Oct 2008 Posts: 157

Eyefinity does work perfect with the opensource driver (radeon).

I'm using the opensource driver with 3 displays and a 5750. I can watch videos without any tearing effects and I don't need 3D accel. Radeon has 2D accel for the evergreens since some months, works like it should.

norg · Posted: Sun Feb 27, 2011 7:26 pm Post subject:

You only have one card and use 3 displays? how did you manage this?

kingfame_147 · Apprentice Joined: 11 Oct 2008 Posts: 157

There is nothing special to manage.
Just insert the card, plug in the displays and configure them with xrandr (or an config file in xorf.conf.d).

There are some limitations, but those lim. also exist with the catalyst driver: You can only use 2x DVI. So if you want 3 displays one of them have to use DP, or an active DVI->DP adapter.

norg · Posted: Mon Feb 28, 2011 2:02 am Post subject:

So what's your xorg.conf or xrandr setting like?
Is it builtin support or do you use xinerama with the driver?
And what windowmanager do you use?
With my card i have 5x mini displayport and i have 3 adapters minidp -> dp for my hp zr24w. So i'm not sure if i can port this to my setup.
Ah and what GPU do you use?

I never heard anything about eyefinity/multi-head support with the opensource driver, but this would be great although i miss good 3D Support and the video acceleration. But trying the os drivers would be worth a try if you can help me and tell me details of your setup.

kingfame_147 · Apprentice Joined: 11 Oct 2008 Posts: 157

Your setup should work. MiniDP -> DP should be no problem.

1) There is nothing special in my xrandr setup, just the orientation of my displays.

norg · Posted: Mon Feb 28, 2011 10:18 pm Post subject:

Well that sounds nice, i should give it a try as the primary use for my workstation is work and not 3D stuff.
But i'm wondering that i never saw any information about multi-head, only dual-head with the OS driver.
Thanks so far.

Just for my interest, what xorg and driver version are you using?

kingfame_147 · Apprentice Joined: 11 Oct 2008 Posts: 157

Well there are not many ppl using the OS driver with more then two displays. I've asked at the mailing list before I tried it, and one of the main developer said that there should be no problem and it should work, and it does.

I'm using xorg-server-1.10.0 and the git version of xf86-video-ati. The OS driver is under heavy development, so I would use the git version if I were you.