For proper multiseat with a single GPU, you need KMS. It won't work with fglrx or nvidia, no matter what you do.
You could resort to Xnest / Xephyr hacks, but those suck.
For proper multiseat with a single GPU, you need KMS. It won't work with fglrx or nvidia, no matter what you do.
You could resort to Xnest / Xephyr hacks, but those suck.
I've been using multiple GPUs to get around that, but the motherboard isn't reporting all card's VBIOS info.
I jumped from nVidia to AMD as I wanted to use three monitors and had been told by some people here that most of the reports of problems with the ATI closed driver were mostly due to end user error or some such.
Unfortunately that wasn't to be the case and up to and including the 10.9 release I would regard the nVidia option as a much better beast if you only need two screens. Some say that the 10.10beta is a thing of beauty but I wont know myself until later today.
I should say that I'm running Ubuntu on a Q6600 CPU and an ATI 5870.
The ATI hardware is beutiful, fast, quiet and efficient and nicely priced but now onto the software aspects.
2D performance I find quite good with some exceptions.
Window resizing becomes terribly slow, as in two seconds between redraws once you go beyond a certain window size and sometimes this becomes more evident depending on how much video RAM is consumed via other windows.
I don't miss Xinerama at all and when ATI's drivers mature the best way to avoid it for a triple head setup will be via an ATI card.
Up until the 10.8 release I was playing games and had no issues while Compiz was enabled. Compiz works mostly well with Eyefinity. At lease no worse than with only two monitors. At the moment I'm not playing games but I still use the Blender 3D modelling app and when it is it's working it's very fast. Depending what other apps are open sometimes Blender wont be rendered correctly unfortunately. I can fix that by shutting down other apps and then restarting Blender. I have Compiz resize the Blender window across two monitors leaving the third open for other tasks such as email, browser, video playback, etc. I could achieve this via two nVidia cards without Xinerama and would only mean I wouldn't be able to drag windows from the double monitor desktop to the single one which isn't a problem on the ATI card, but there are rendering issues though with ATI.
The closed driver makes Compiz aware of the screens and there's no need for the "fake xinerama" hacks with ATI. Window positioning isn't one of the problems fglrx has. It deals with that completely automagically.
I currently don't have my monitors layed out this way so haven't tested that myself. I just have three 24" Acers, each at 1920x1200 in normal landscape orientation for a single desktop of 5760x1200.
As above, I haven't tested this.
I didn't find manual editing of xorg.conf necessary at any stage with ATI's fglrx. I simply used the command "sudo aticonfig --initial -f" to initialise xorg.conf after installing the driver and all other configuration including the enablement of the monitor layout and Eyefinity was done via ATI's graphics config utility.
I should add that the more windows and open the greater the chance of odd behaviour rearing its ugly head from fglrx.
Over time performance degrades the longer my uptime. I get the feeling there might be some quirks in the drivers memory management perhaps. But after a couple of days up a reboot brings back the spritelyness.
I drive my third monitor via an active DisplayPort to DVI adapter. When staring video playback via some software (it'll be because the the playback mode the software's using), the DisplayPort gets re-initialised in some way causing that monitor to become black momentary. Annoying but not a real problem in itself.
Over time I've seen some improvements here and there in the driver so bottom line is ATI/AMD are making progress.
Lets hope the 10.10 release fixes the dodgy behaviour issues and then Linux can provide a great triple head experience via ATI.
Remember that these are the kinds of things you can expect with the current release driver on a 5000 series card under Ubuntu. Some are saying the beta release of 10.10 is great for them so there's definite hope on the horizon. I'll know myself later in the day.
edit..........
I haven't noticed any of this on my 5870. Then again I'm not using compiz.
For sure.
I have to use multiple nvidia GPUs at work and having to run the separate X screens without xinerama is a pain, let me tell you. I would almost be ok with living with the software accelerated xinerama just to get around it, but not quite.
Again, I've not seen any of this behavior.
The same thing happens to all of my monitors (one native display port, one HDMI, and one DVI): they all go blank for about a second if I turn on one of the three monitors. So I don't think it's a problem only with the DisplayPort/adapter.
Myself and some others over on the ubuntu forums, are starting to make progress with this little over 2year bug.
We now have managed to compile and have a none screen flashing situation, before video playback with mplayer. I believe it has to do with how some media players, call to x11. As we've disabled x11 with mplayer, and it's working. Also how this only seems to happen with certain players, VLC/mplayer, and how it doesn't happen with players like Totem, and Dragon Player (kde default)
I did have a thread on this forum about the same problem, but as I was getting more support from the ubuntu forums, I've stuck with that one.
Thread on this forum
Ubuntu Forum link