Hi all,
My organization has a 12-monitor video wall powered by a single Linux machine with Fedora 18 installed. Previously, we have used a single AMD Eyefinity card and then used splitter boxes to feed the signal out to the 12 monitors (6 outputs from the Eyefinity card become 12 outputs to the monitors). This was workable, but had some problems.

Recently, we have decided to upgrade to two AMD 7870 Eyefinity cards with the idea of ditching the splitter boxes (which were starting to fail) and possibly getting better performance. Unfortunately, we are running into some problems with this set-up.

1) So far, at best, the machine will recognize two separate 6-monitor displays. If Xinerama is active, then windows can span the two displays, but 3D performance is extremely poor and the two displays are out of sync. Additionally, when a window is maximized (set to "full screen") it only does so in a single monitor. With Xinerama disabled, 3D performance returns but only for one 6-monitor display at a time and windows can no longer span the the two displays or be dragged between them.

2) We tried enabling the MGPU_SLS option after creating a GPU chain, but that did not provide any benefit.

We have seen the video by Matthew Tippett showing a Linux box with 4 cards doing what we are attempting - this was part of our reason for going this route. Hopefully, there is some solution to get the two cards to work together properly as a single display.

Here is our xorg.conf as it currently stands:

Code:
Section "ServerLayout"
	Identifier     "aticonfig Layout"
	Screen      0  "aticonfig-Screen[0]-0" 0 0
	Screen         "aticonfig-Screen[1]-0" 2732 0
EndSection

Section "Module"
EndSection

Section "ServerFlags"
	Option      "Xinerama" "on"
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   "aticonfig-Monitor[1]-0"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
EndSection

Section "Monitor"
	Identifier   "0-DFP1"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "0 0"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "0-DFP5"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "1366 0"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "0-DFP17"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "0 768"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "0-DFP21"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "1366 768"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "0-DFP9"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "0 1536"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "0-DFP13"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "1366 1536"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "1-DFP1"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "0 0"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "1-DFP5"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "1366 0"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "1-DFP17"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "0 768"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "1-DFP21"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "1366 768"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "1-DFP9"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "0 1536"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Monitor"
	Identifier   "1-DFP13"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
	Option	    "PreferredMode" "1366x768"
	Option	    "TargetRefresh" "60"
	Option	    "Position" "1366 1536"
	Option	    "Rotate" "normal"
	Option	    "Disable" "false"
EndSection

Section "Device"
	Identifier  "aticonfig-Device[0]-0"
	Driver      "fglrx"
	Option	    "Monitor-DFP1" "0-DFP1"
	Option	    "Monitor-DFP5" "0-DFP5"
	Option	    "Monitor-DFP17" "0-DFP17"
	Option	    "Monitor-DFP21" "0-DFP21"
	Option	    "Monitor-DFP9" "0-DFP9"
	Option	    "Monitor-DFP13" "0-DFP13"
	BusID       "PCI:6:0:0"
EndSection

Section "Device"
	Identifier  "aticonfig-Device[1]-0"
	Driver      "fglrx"
	Option	    "Monitor-DFP1" "1-DFP1"
	Option	    "Monitor-DFP5" "1-DFP5"
	Option	    "Monitor-DFP17" "1-DFP17"
	Option	    "Monitor-DFP21" "1-DFP21"
	Option	    "Monitor-DFP9" "1-DFP9"
	Option	    "Monitor-DFP13" "1-DFP13"
	BusID       "PCI:5:0:0"
EndSection

Section "Screen"
	Identifier "aticonfig-Screen[0]-0"
	Device     "aticonfig-Device[0]-0"
	DefaultDepth     24
	SubSection "Display"
		Viewport   0 0
		Virtual   2732 2304
		Depth     24
	EndSubSection
EndSection

Section "Screen"
	Identifier "aticonfig-Screen[1]-0"
	Device     "aticonfig-Device[1]-0"
	DefaultDepth     24
	SubSection "Display"
		Viewport   0 0
		Virtual   2732 2304
		Depth     24
	EndSubSection
EndSection