Below is the typical X configuration file that was first created on Debian system. 
There may be some minor differencies on other distros.  Those differencies may reflect 
different font paths, mouse driver and ways to set up monitor. The best way to create 
your new working config file - is to start off the copy of your existing X file that 
was proven to work. 

Other than that, one may need to alter Monitor sections to reflect actual refresh rates 
of the monitors to be used, and Device section, BusID entry - that should be set to actual 
PCI bus ID of your Matrox adapter. Driver line should be edited to have "mtx" in it.
In Screen section one could set desired resolutions and default pixel depth. 

Section "ServerLayout"
        Identifier     "Double dual-merge"
	Screen		"screen0" LeftOf "screen1"
	Screen	       "screen1"
	InputDevice    "Mouse0" "CorePointer"
        InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "ServerFlags"
	Option "Xinerama"
EndSection

Section "Files"
	FontPath	"unix/:7100"			# local font server
	# if the local font server has problems, we can fall back on these
	FontPath	"/usr/lib/X11/fonts/misc"
	FontPath	"/usr/lib/X11/fonts/cyrillic"
	FontPath	"/usr/lib/X11/fonts/100dpi/:unscaled"
	FontPath	"/usr/lib/X11/fonts/75dpi/:unscaled"
	FontPath	"/usr/lib/X11/fonts/Type1"
	FontPath	"/usr/lib/X11/fonts/CID"
	FontPath	"/usr/lib/X11/fonts/Speedo"
	FontPath	"/usr/lib/X11/fonts/100dpi"
	FontPath	"/usr/lib/X11/fonts/75dpi"
EndSection

Section "Module"
	Load	"GLcore"
	Load	"bitmap"
	Load	"dbe"
	Load	"ddc"
	Load	"extmod"
	Load	"freetype"
	Load	"glx"
	Load	"int10"
	Load	"record"
	Load	"speedo"
	Load	"type1"
	Load	"vbe"
EndSection

Section "InputDevice"
        Identifier  "Keyboard0"
        Driver      "keyboard"
	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" "no"
EndSection

Section "Monitor"
        Identifier   "Monitor0"
        VendorName   "Monitor Vendor"
        ModelName    "Monitor Model"
        HorizSync   30-90
        VertRefresh 50-60
        Option "dpms"
EndSection

Section "Monitor"
        Identifier   "Monitor1"
        VendorName   "Monitor Vendor"
        ModelName    "Monitor Model"
        HorizSync   30-90
        VertRefresh 50-60
        Option "dpms"
EndSection

Section "Device"
	Identifier   "device0"
        Driver       "mtx"
        BusID		"PCI:2:0:0"
	Option 	     "QID"
	Screen 0
EndSection

Section "Device"
	Identifier   "device1"
        Driver       "mtx"
        BusID		"PCI:2:0:0"
	Option       "QID"
	Screen 1
EndSection

Section "Screen"
	Identifier   "screen0"
        Device       "device0"
        Monitor      "Monitor0"
	DefaultDepth	24	
#	Option "Rotate" "CW"
	Subsection "Display"
        	Depth      8 
                Modes      "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480" 
	EndSubsection
	
	Subsection "Display"
        	Depth       16
                Modes       "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480" 
	EndSubsection

	Subsection "Display"
        	Depth       24
               Modes        "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480" 
	EndSubsection

	Subsection "Display"
        	Depth       30
                Modes        "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480" 
	EndSubsection
EndSection

Section "Screen"
	Identifier   "screen1"
        Device       "device1"
        Monitor      "Monitor1"
	DefaultDepth	24	
	Subsection "Display"
        	Depth      8 
                Modes       "1600x1200" "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480" 

	EndSubsection
	
	Subsection "Display"
        	Depth       16
                Modes       "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480" 
	EndSubsection
	
	Subsection "Display"
        	Depth       24
                Modes        "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480" 
	EndSubsection

	Subsection "Display"
        	Depth       30
                Modes       "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480" 
	EndSubsection
EndSection
