6 Monitor eyefinity setup working!

[kdowley]

Using a xeon e3 and a powercolor 6870 eyefinity 6 I have successfully gotten 6 24" monitors to display in centos 6! The whole process was mostly trial and error as the amd control panel is a bit flaky. I ended up installing a few different distros until I found one that played nice with the hardware (redhat 5.7 was a huge hassle and never worked).

However, moving windows is very slow. Windows move across the screen about 1 FPS even though the mouse doesn't have much lag. Are there any ways to speed this up?

Also, there is quite a bit of flickering on monitors 5 and 6. Currently they are connected via DVI cables though all monitors have displayport inputs. I have ordered 2 more displayport cables and hopefully this will eliminate the flickering as I'm thinking the culprit is DVI.

But still the speed is so slow. If I were able to fix that I'd be rockin!

[rohcQaH]

My usual advice in these situations is: kill the AMD control panel with fire. Then with tactical nukes. Then try fire again.

IIRC the control panel defaults to implementing a Xinerama-based multimonitor solution, which is an ancient and mostly deprecated method for multiscreening. Why deprecated? Because it's slow, problematic and somewhat incompatible with compositing. It was ment for multiscreen solution with one gfx card per monitor, not for your setup. Try moving a window across multiple monitors, if you see each part of the window redraw separately, that's your problem.

If that's the case, undoing the mess the amd control panel did, then configuring a proper XRandR-based multiscreen setup would likely solve a lot of your problems.


Alas, unless you paste your xorg.conf, the output of xrandr and maybe a screenshot of the respective pages of the amd control panel, it's difficult to diagnose from afar. And it's very important to post a photo of your monitor setup, because I like to drool over such things

[kdowley]

rohcQaH,

Thank you for your post! I will try doing exactly what you recommend and will report on the results. I will post pictures and outputs a bit later today.

Also, the redraw problem is spot on and is exactly whats happening. It seems the more monitors I add the slower it gets. Though the redraw problem isn't only across monitors but when moving any window.

Do you think you can point me in the right direction for configuring XRandR for this particular setup?

[rohcQaH]

Do you think you can point me in the right direction for configuring XRandR for this particular setup?

unless fglrx has some xrandr bugs with >2 monitors, it's as simple as a dual-monitor-layout. You just repeat the command to add monitors a couple of times.
Use amdcc or aticonfig or whatever to setup a basic single monitor layout. If your xorg.conf contains multiple monitors or even cards, you're doing it wrong. Then use the xrandr command to configure everything.

Try searching for a distro-specific randr guide, there should be one. Otherwise, pick any for a different distrib. Also consult man xrandr. The commands are really simple, the biggest gotcha is the need to add a larger "Virtual" size to the Screen section of your xorg.conf when your desktop gets larger than 2048x2048. Again, see those guides for details.

[kdowley]

I reinstalled the os, this time with redhat 6.1 and when I installed the 11.8 driver chose to not install the amd control panel.

Once the install completed, I ran 'aticonfig --initial' and from there only edited xorg.conf

My 'xrandr -q' is pretty simple, 'Screen 0' is DFP1-DFP6 with a maximum resolution of 5760 x 2160 (as defined as 'virtual' space in xorg.conf)

Below is my xorg.conf file:

Section "ServerLayout"
	Identifier     "aticonfig Layout"
	Screen      0  "aticonfig-Screen[0]-0" 0 0
EndSection

Section "Module"
EndSection

Section "Monitor"
	Identifier   "aticonfig-Monitor[0]-0"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
EndSection

Section "Monitor"
        Identifier "dfp1"
        Option "Position" "0 1080"
EndSection

Section	"Monitor"
        Identifier "dfp2"
        Option "Position" "0 0"
EndSection

Section "Monitor"
        Identifier "dfp3"
        Option "Position" "1920 1080"
EndSection

Section "Monitor"
        Identifier "dfp4"
        Option "Position" "1920 0"
EndSection

Section "Monitor"
        Identifier "dfp5"
        Option "Position" "3840 1080"                
EndSection

Section "Monitor"
        Identifier "dfp6"
        Option "Position" "3840 0"                
EndSection


Section "Device"
	Identifier  "aticonfig-Device[0]-0"
	Driver      "fglrx"
	BusID       "PCI:1:0:0"
	Option		"monitor-DFP1" "dfp1"
	Option		"monitor-DFP2" "dfp2"
	Option		"monitor-DFP3" "dfp3"
	Option		"monitor-DFP4" "dfp4"
	Option		"monitor-DFP5" "dfp5"
	Option		"monitor-DFP6" "dfp6"
EndSection

Section "Screen"
	Identifier "aticonfig-Screen[0]-0"
	Device     "aticonfig-Device[0]-0"
	Monitor    "aticonfig-Monitor[0]-0"
	DefaultDepth     24
	SubSection "Display"
		Viewport   0 0
		Depth     24
		Modes	"1920x1080"
		Virtual	5760 2160
	EndSubSection
EndSection

Overall it was fairly simple to configure once I found a good source online to explain how to edit xorg.conf.

Things aren't perfect though. The speed is still slow when moving windows around, though it's improved from before. I'm not sure if it's something I'm just going to have to live with, but it seems a bit crazy considering how beefy the video card is. It feels like it's not using all it's power, or the voltage needs to be bumped up somewhere, or hardware acceleration needs to be enabled.

Any ideas on how to combat this?

Thanks!

[rohcQaH]

Which window manager are you using? If a compositing window manager tries to redraw the whole screen when moving a window, that might get a bit slow at your resolution. Is compositing enabled? If so, what happens when you temporarily disable it?

Another check you might perform is to switch off monitors one by one to reduce your workspace size (xrandr --output DFP1 --off etc) and see if performance improves.

[kdowley]

Which window manager are you using? If a compositing window manager tries to redraw the whole screen when moving a window, that might get a bit slow at your resolution. Is compositing enabled? If so, what happens when you temporarily disable it?

Another check you might perform is to switch off monitors one by one to reduce your workspace size (xrandr --output DFP1 --off etc) and see if performance improves.

I'm using gnome. I tried disabling compositing and no dice on that one either. Performance does seem to be effected by the number of displays connected, but it seems like too much power is sapped when there's 3 or 4 connected even that there has got to be a root cause somewhere. The GPU is a 6870 with 2GB of RAM, there has got to be some way to turn on even a fraction of that power so windows run smoother. Once that gets fixed, this 6 monitor setup will be flawless.

[kdowley]

Great post,we should learn from you Does it really work?

Oh ya, it works. I'm starting to think the issues with my 2d slowness could be due to the ati fglrx driver and it's quite possible that switching to the open source driver might cure all of the slowdown with moving windows. However, in my application, that doesn't matter much as once I set up my 6 browsers windows, I won't have to move them around... thats kinda the point of having 6 monitors in the first place.

[AlbertP]

If the xrandr output does not contain 6 different monitors (all displayport and DVI connections listed under Screen 0), you're still using Xinerama somehow and not XRandR.

[smitchell]

With 4 monitors, I found that using Enlightenment E17 instead of normal Gnome or Kde window managers speeded things up noticably.
E17 has some difficulty compiling under Slackware 64, due to the multilib nature of Slackware64 (putting things in /lib or /lib64 and finding them later), but on non-multi-lib distributions that shouldn't be concern as there are many pre-made packages for E-17.

It really makes a difference in speed on the screen.

Since you can install it and try it temporarily without ditching your other window managers, I encourage you to give it a go.