The first thing you might notice when you replace your old format display with a wide-screen display is Xorg not recognizing the change in aspect ratio. In the default VESA modes, there are several modes that are for (slightly) wider-than-normal laptop displays, but none are true 16x9. In the more recent Xorg releases, you don't really specify your modes like in the old days (unless it has trouble with the detection of your particular hardware setup). Even then, it usually suffices to specify the ranges of sync frequencies for your monitor, and X will (usually) sort out the best display mode.
Well, now there's one more apparently required setting, since Xorg just doesn't seem to want to recognize a wide-screen mode without it (see below for an example). In addition to the standard parameters, the key one seems to be in the graphics device section:
Option "DDCMode" "true"
The VESA and Radeon framebuffer drivers both seem to handle the 1440x900 mode just fine, and it may help to add the correct mode to your kernel parameters in grub.conf (see any recent boot-splash docs for details). Here's my current set of kernel parameters; ignore the md device stuff:
kernel /vmlinuz-2.6.22.9 ro root=/dev/md2 md=2,/dev/sda2,/dev/sdb2 video=ywrap,mtrr,radeonfb:1440x900@60 doscsi max_luns=7
Here is the complete xorg.conf file:
Section "ServerLayout"
Identifier "X.org Configured"
Screen 0 "Screen0" 0 0
Screen 0 "aticonfig-Screen[0]" 0 0
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
Option "AIGLX" "true"
EndSection
Section "Files"
FontPath "/usr/share/fonts/misc"
FontPath "/usr/share/fonts/75dpi"
FontPath "/usr/share/fonts/100dpi"
FontPath "/usr/share/fonts/TTF"
FontPath "/usr/share/fonts/Type1"
FontPath "/usr/share/fonts/artwiz"
FontPath "/usr/share/fonts/cronyx/100dpi/:unscaled"
FontPath "/usr/share/fonts/cronyx/misc/:unscaled"
FontPath "/usr/share/fonts/cronyx/75dpi/:unscaled"
EndSection
Section "Module"
Load "glx"
Load "extmod"
Load "dbe"
Load "record"
Load "xtrap"
Load "dri"
Load "freetype"
Load "type1"
SubSection "extmod"
Option "omit xfree86-dga" # don't initialise the DGA extension
EndSubSection
EndSection
Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
EndSection
Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/input/mice"
Option "ZAxisMapping" "4 5"
EndSection
Section "Monitor"
Identifier "wide_lcd"
VendorName "LG Electronics"
ModelName "L196W"
HorizSync 30.0 - 82.0
VertRefresh 56.0 - 75.0
Option "DPMS" "true"
EndSection
Section "Device"
Identifier "Card0"
Driver "radeon"
VendorName "ATI Technologies Inc"
BoardName "RV350 [Mobility Radeon 9600 M10]"
BusID "PCI:1:0:0"
Option "AGPMode" "8"
#Option "AGPFastWrite" "true"
Option "EnableDepthMoves" "true"
Option "EnablePageFlip" "true"
Option "NoBackBuffer" "false"
Option "RenderAccel" "on"
Option "ColorTiling" "on"
Option "XAANoOffscreenPixmaps" "true"
Option "DRI" "true"
Option "DDCMode" "true"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "wide_lcd"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 1
Modes "1440x900"
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 4
Modes "1440x900"
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 8
Modes "1440x900"
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 15
Modes "1440x900"
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 16
Modes "1440x900"
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 24
Modes "1440x900"
EndSubSection
EndSection
Section "DRI"
Mode 0666
EndSection
Section "Extensions"
Option "Composite" "Enable"
EndSection
The above should work for recent versions of Xorg 1.3.0 and 1.4 (and possibly older versions), as well as wide-screen displays from two different vendors (both using the analog VGA output), with the xorg radeon driver (not the vendor-supplied one) on several card models (RV250/300/350). The additional parameters in the xorg.conf file above pertain to Gnome 2.20.1 and metacity 2.20.0 (with the compositing extension enabled). 3D performance and stability are both very good, but beryl sucks a huge amount of CPU to provide the desktop effects. You can extract the sync ranges and resolutions from the *.inf file that usually comes on the CD (with your monitor).