Ubuntu: manage two monitors

How manage two monitors in Ubuntu system?

First of all, you have tu use ATI fglrx driver, obiously if you have ATI graphic card

Follow the Unofficial ATI Linux driver wiki to 1) install and configuring the driver and 2) enable two monitors.

In short:

1. install the driver:

sudo apt-get install xorg-driver-fglrx

2. you shouldn’t need to update xorg.conf, just verify that fglrx is present in this file:

[...]
Section "Device"
Identifier "ATI Technologies Inc Radeon Mobility X700 (PCIE)"
Driver "fglrx"
[...]
EndSection
[...]

3. enables support fro Big-Desktop, and places the two monitors next to each other (see thread about ATI Big Desktop)

sudo aticonfig --desktop-setup=horizontal --sync-vsync=on --add-pairmode=Width0xHeight0+Width1xHeight1

4. enable two monitors on the fly:

aticonfig --enable-monitor=lvds,crt1 --effective=now
Note: in
aticonfig --enable-monitor=string, string
string can be one of the following set, separated by commas: none, crt1, crt2, lvds, tv, tmds1, tmds2, auto. Check out connected and enabled monitors using:
aticonfig --query-monitor