Four Monitor X-Windows

= Objective =

To get my four monitor X-Windows configuration to work properly with Xinerama. Currently, the mouse pointer moves among all monitors, but cannot seem to drag open application window between monitors of differing cards.

Appearance

Below are side-to-side screen shots of virtual screen0 (left-hand side) and virtual screen1 (right-hand side)...
Basically, you are looking at what I see across 4 monitors...
Notice spanned wallpaper is repeating for virtual screen0 and virtual screen1.

General Information

Video Cards

• ATI Radeon X1600 Pro PCI-E (Sapphire)
• Nvidia GEForce 8400 GS PCI

Note: Each card has dual port VGA / DVI

OS Information

Linux Distribution: Ubuntu Studio 10.10
Kernel Version: Linux studio 2.6.35-23-generic #37-Ubuntu SMP Fri Nov 5 19:16:29 UTC 2010 x86_64 GNU/Linux

X-Windows Information

[ xorg.conf ]

Additional Information

Xrandr Commands (at system startup - Added to "Startup Application"):

• xrandr --output VGA-0 --mode 1440x900 --pos 1440x0 --screen 1 # (right two monitors)
• xrandr --output VGA2 --mode 1440x900 --pos 1440x0 --screen 0 # (left two monitors)

Other Observations

• Able to get 4 monitors running in XWindows with mouse pointer spanning all 4 monitors (but can't span open applications between cards).
• Need to set PCI card as then primary Video default in BIOS to make 4 monitors work (auto didn't seem to work correctly).
• When enabling xinerama (i.e. In "Server Layout: Option "Xinerama" "1" ), screen 0 is mirrored, and does not allow mouse pointer to move to other card (although other card's monitors span correctly. Background picture shows in screen 1, but only background colour displays in screen 0).
• Radeon error upon boot-up: error during ACPI method call
• I seem to have better luck when setting Nvidia card to older driver such as "nv" as opposed to "radeon". Unfortunately, also seem to lose better graphics capabilities...

Additional information from grep radeon /var/log/messages:

Nov 18 22:03:56 studio kernel: [ 17.111500] [drm] radeon defaulting to kernel modesetting.
Nov 18 22:03:56 studio kernel: [ 17.111505] [drm] radeon kernel modesetting enabled.
Nov 18 22:03:56 studio kernel: [ 17.111570] radeon 0000:01:00.0: enabling device (0000 -> 0003)
Nov 18 22:03:56 studio kernel: [ 17.111580] radeon 0000:01:00.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16
Nov 18 22:03:56 studio kernel: [ 17.261545] radeon 0000:01:00.0: VRAM: 256M 0x00000000 - 0x0FFFFFFF (256M used)
Nov 18 22:03:56 studio kernel: [ 17.261549] radeon 0000:01:00.0: GTT: 512M 0x10000000 - 0x2FFFFFFF
Nov 18 22:03:56 studio kernel: [ 17.261663] radeon 0000:01:00.0: radeon: using MSI.
Nov 18 22:03:56 studio kernel: [ 17.261692] [drm] radeon: irq initialized.
Nov 18 22:03:56 studio kernel: [ 17.330580] [drm] radeon: 256M of VRAM memory ready
Nov 18 22:03:56 studio kernel: [ 17.330583] [drm] radeon: 512M of GTT memory ready.
Nov 18 22:03:56 studio kernel: [ 17.332863] [drm] radeon: 1 quad pipes, 2 z pipes initialized.
Nov 18 22:03:56 studio kernel: [ 17.348456] [drm] radeon: ring at 0x0000000010000000
Nov 18 22:03:56 studio kernel: [ 17.348699] [drm] radeon: ib pool ready.
Nov 18 22:03:56 studio kernel: [ 17.790148] fb0: radeondrmfb frame buffer device
Nov 18 22:03:56 studio kernel: [ 17.790227] [drm] Initialized radeon 2.5.0 20080528 for 0000:01:00.0 on minor 0

Comments / Suggestions / Assistance

Please add any suggestions here... Thanks :)