Big Desktop

As opposed to running dual-head, an alternative ATI Linux option is to use Big Desktop. ATI Big Desktop stretches one X server across two displays, rather than using a separate X server for each of the heads. ATI's Big Desktop is similar to NVIDIA's TwinView under Linux. Outside of the ATI dual-head and Big Desktop configurations, mirror and clone modes are also available for displaying the same content across multiple displays. ATI Big Desktop can be easily activated by using aticonfig --dtop=horizontal (if using a standard horizontal dual monitor setup), as well as specifying any other optional parameters. I have been trying out ATI Big Desktop on my system for two days now, and so far it has worked surprisingly well. Last time I had tried out NVIDIA TwinView with the 7800GTX, I personally wasn't fond of its X spanning for whatever reason. With ATI Big Desktop and the X1800XT, I haven't yet run into any stability problems or similar issues during testing. I'll work on writing more Big Desktop information soon. For those that haven't tampered with Big Desktop, below is a sample xorg.conf to see the changes made by aticonfig.

Section "ServerLayout"
	Identifier     "Default Layout"
	Screen      0  "aticonfig-Screen[0]" 0 0
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"
	RgbPath      "/usr/X11R6/lib/X11/rgb"
	FontPath     "unix/:7100"
EndSection

Section "Module"
	Load  "dbe"
	Load  "extmod"
	Load  "fbdevhw"
	Load  "glx"
	Load  "record"
	Load  "freetype"
	Load  "type1"
	Load  "dri"
EndSection

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "kbd"
	Option	    "XkbModel" "pc105"
	Option	    "XkbLayout" "us"
EndSection

Section "InputDevice"
	Identifier  "Mouse0"
	Driver      "mouse"
	Option	    "Protocol" "IMPS/2"
	Option	    "Device" "/dev/input/mice"
	Option	    "ZAxisMapping" "4 5"
	Option	    "Emulate3Buttons" "yes"
EndSection

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

Section "Device"
	Identifier  "aticonfig-Device[0]"
	Driver      "fglrx"
	Option	    "DesktopSetup" "horizontal"
	BusID       "PCI:1:0:0"
EndSection

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

Section "DRI"
	Group        0
	Mode         0666
EndSection