John Haggerty said...

+It looks like my real problem is going to be the dual monitors in SL3.

That depends on what you really need.  You may be fine
with your needs.  If it weren't for the Cadence/GL issues,
I believe all of these would work for us, and we'd have
dropped the G450s in favor of the nVidia and ATI cards
because of speed.

+I guess the guidance I need is how to configure the dual head graphics 
+cards; what do you have to do to the Matrox cards, for example, to get 
+the dual heads working?

The easiest thing to do is download the "mgapdesk" rpm.
Mgapdesk is their GUI-based desktop config tool.  It
lets you configure things in one of several ways-- as
clone monitors, or one big monitor with the desktop
apps only on one of them, or one big desktop with the
desktop apps across both.  You can configure for
monitors arranged horizontally or vertically, and swap
which is which.  I am attaching one of our config files
as a sample.  There are other tweaks you can make but
this is a decent baseline.  One oddity we ran into was
that when we switched from RH8 to RHEL3/SL3 we had to
drop the max. resolution with these cards on our most
common monitors.  YMMV.

+This is a PCIe motherboard, so it looks like 
+I'd want the P650 if I need to trade in my PNY cards, since that's a 
+PCIE x16 dual DVI jobby.  But if I get the driver from the Matrox site 
+(http://www.matrox.com/mga/support/drivers/latest/home.cfm) what do I 
+have to do to get the second head working?  I can't see it in the SL3 
+docs, and SL4 has display configuration for the second monitor.  The 
+nvidia driver actually works for the first head with the PNY card; it's 
+just not clear what's needed to get the second half working.

I wouldn't swap cards just yet.

Much to my chagrin, I can't find an nVidia sample of
an XF86Config file here.  (I'm about to revisit those,
so I'll have to start over.)  But we did it before from
basic web searches.  Try googling for "nvidia Linux dual head OR monitor".
The gentoow wiki (as noted by someone else) is a good
place to start.  When I have a good config file I'll be
happy to post it here.

I believe that dri and glx are mutually exclusive with
the nVidia driver.



# XFree86 4 configuration created by redhat-config-xfree86

Section "ServerLayout"
	Identifier     "Matrox PowerDesk configured."
	Screen      0  "Display Merged" 0 0
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"
	RgbPath      "/usr/X11R6/lib/X11/rgb"
	ModulePath   "/usr/X11R6/lib/modules"
	FontPath     "tcp/fonts.eng.intrinsity.com:7100"
	FontPath     "unix/:7100"
	FontPath     "/usr/X11R6/lib/X11/fonts/misc/"
EndSection

Section "Module"
	Load  "vnc"
	Load  "dbe"
	Load  "dri"
	Load  "extmod"
	Load  "glx"
	Load  "record"
	Load  "xtrap"
	Load  "speedo"
	Load  "type1"
EndSection

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "keyboard"
EndSection

Section "InputDevice"
	Identifier  "Mouse0"
	Driver      "mouse"
	Option	    "Protocol" "auto"
	Option	    "Device" "/dev/mouse"
EndSection

Section "Monitor"
	Identifier   "Display 1"
	VendorName   "IQT"
	ModelName    "ImageQuest Q910"
	HorizSync    30.0 - 110.0
	VertRefresh  50.0 - 150.0
	Option	    "DPMS"
EndSection

Section "Monitor"
	Identifier   "Display 2"
	VendorName   "IQT"
	ModelName    "ImageQuest Q910"
	HorizSync    30.0 - 110.0
	VertRefresh  50.0 - 150.0
EndSection

Section "Monitor"
	Identifier   "Display Merged"
	VendorName   "IQT"
	ModelName    "ImageQuest Q910"
	HorizSync    30.0 - 110.0
	VertRefresh  50.0 - 150.0
EndSection

Section "Device"
	Identifier  "MATROX CARD 1"
	Driver      "mga"
	VendorName  "Matrox Graphics, Inc."
	BoardName   "Matrox Millennium G450"
	Option	    "hw cursor" "off"
	BusID       "PCI:1:0:0"
EndSection

Section "Device"
	Identifier  "MATROX CARD 2"
	Driver      "mga"
	VendorName  "Matrox Graphics, Inc."
	BoardName   "Matrox Millennium G450"
	Option	    "hw cursor" "off"
	BusID       "PCI:1:0:0"
	Screen      1
EndSection

Section "Screen"
	Identifier "Display 1"
	Device     "MATROX CARD 1"
	Monitor    "Display 1"
	DefaultDepth     24
	SubSection "Display"
		Depth     1
	EndSubSection
	SubSection "Display"
		Depth     4
	EndSubSection
	SubSection "Display"
		Depth     8
		Modes    "1280x1024" "1152x864" "1024x768" "800x600" "640x480"
	EndSubSection
	SubSection "Display"
		Depth     15
	EndSubSection
	SubSection "Display"
		Depth     16
		Modes    "1280x1024" "1152x864" "1024x768" "800x600" "640x480"
	EndSubSection
	SubSection "Display"
		Depth     24
		Modes    "1280x1024" "1152x864" "1024x768" "800x600" "640x480"
	EndSubSection
EndSection

Section "Screen"
	Identifier "Display 2"
	Device     "MATROX CARD 2"
	Monitor    "Display 2"
	DefaultDepth     24
	SubSection "Display"
		Depth     24
		Modes    "1280x1024" "1152x864" "1024x768" "800x600" "640x480"
	EndSubSection
	SubSection "Display"
		Depth     8
		Modes    "1280x1024" "1152x864" "1024x768" "800x600" "640x480"
	EndSubSection
	SubSection "Display"
		Depth     16
		Modes    "1280x1024" "1152x864" "1024x768" "800x600" "640x480"
	EndSubSection
EndSection

Section "Screen"

#--	SubSection "Display"
#--		Virtual   2560 1024
#--		Depth     24
#--		Modes    "1280x1024" "1152x864" "1024x768" "800x600" "640x480"
#--	EndSubSection
	Identifier "Display Merged"
	Device     "MATROX CARD 1"
	Monitor    "Display Merged"
	DefaultDepth     24
	Option	    "Monitor2Position" "RightOf"
	Option	    "MetaModes" "1400x1050-1400x1050 1280x1024-1280x1024 1152x864-1152x864 1024x768-1024x768 1280x1024 1152x864 1024x768 800x600 640x480 "
	Option	    "Monitor2HSync" "30.0-110.0 "
	Option	    "Monitor2VRefresh" "50.0-150.0 "
	Option	    "MergedFB"
	Option      "passwordFile" "/export/home/meo/.vnc/passwd"
	SubSection "Display"
		Virtual   2800 1050
		Depth     24
		Modes    "1400x1050" "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480"
	EndSubSection
EndSection