Configuring Dual Monitors in Ubuntu

The main HowTo for configuring dual-monitor support on Ubuntu is http://ubuntuforums.org/showthread.php?t=221174. I've included notes on how I configured dual monitor support below. I've also attached working /etc/X11/xorg.conf files.

Determine which chipset you have

Use the lspci command. If you grep for VGA that should isolate the line you want.

# lspci|grep VGA
01:05.0 VGA compatible controller: ATI Technologies Inc Radeon 3100 Graphics

NVidia-based chipsets

• You need to use the nvidia binary/"restricted" drivers. When I installed Ubuntu Gutsy Gibbon it offered to install the restricted module for me. You can manually install the driver as follows:
  • sudo apt-get install linux-restricted-modules-`uname -r` nvidia-glx-new
  • For systems older than Hardy Herron (8.04)
    • sudo nvidia-glx-config enable
  • For Hardy Herron (8.04) and newer systems
    • sudo apt-get install nvidia-settings
• The easiest way to confirm dual-monitor support is to run 'sudo nvidia-settings'
  • Under monitors make sure to enable all monitors that you wish to use
  • There are two "modes" that you can use to get dual-monitor support working: TwinView (binary-only) and Xinerama (open-standard). TwinView is the recommend mode to use as it knows how to use the hardware acceleration of the NVidia card.
  • Once you've made the relevant changes, save and restart X11 (logout/login).

ATI-based chipsets

• You need to use the ati binary/"restricted" drivers. When I installed Ubuntu Gutsy Gibbon it offered to install the restricted module for me. You can manually install the driver as follows:
  • sudo apt-get install linux-restricted-modules-`uname -r` fglrx-control
• The easiest way to confirm dual-monitor support is to run 'sudo fireglcontrol'
  • Under Desktop Setup select 'Big Desktop Horizontal'.
  • You may also need to change the primary monitor.
  • Once you've made the relevant changes, save and restart X11 (logout/login).

I had trouble getting the fglrx driver in Ubuntu working, so I grabbed the latest drivers from ATI and built those:

• sh ati-driver-installer-8.42.3-x86.x86_64.run --buildpkg Ubuntu/7.10
• sudo dpkg -i fglrx-kernel-source_8.42.3-1_i386.deb fglrx-amdcccle_8.42.3-1_i386.deb xorg-driver-fglrx_8.42.3-1_i386.deb
• cd /usr/src; sudo tar -xf fglrx.tar.bz2
• sudo m-a build fglrx
• sudo dpkg -i fglrx-kernel-2.6.22-14-generic_8.42.3-1+2.6.22-14.46_i386.deb
• sudo amdcccle
  • Under Display Manager-> Display Modes select "Big Desktop" mode.
  • Once you've made the relevant changes, save and restart X11 (logout/login).

-- DavidBartley - 07 Nov 2007