There seems some issue with optimus dual video systems. You need to open your terminal and enter the commands below:
First remove current Nvidia installation.
sudo apt-get purge nvidia*
sudo apt-get purge bumblebee*
sudo apt-get update
sudo apt-get dist-upgrade
Install Kernel header if didn't already
sudo apt-get install linux-headers-generic
Then install bumblebee using below commands:
sudo add-apt-repository ppa:bumblebee/stable
For more up-to-date nvidia drivers, you need to add another PPA. As of 12.04, this is still necessary for Nvidia GT 6xxM cards. It may be optional for the GT 4xxM and GT 5xxM series on 12.04. When in doubt, just install it. The command is:
sudo add-apt-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get update
Install Bumblebee using the proprietary nvidia driver:
sudo apt-get install bumblebee bumblebee-nvidia
Reboot or re-login
If you have 32-bit applications like Wine, and run 11.10 Oneiric or later, you will need extra libraries:
sudo apt-get install virtualgl-libs:i386
Allow yourself to use Bumblebee by adding yourself to the 'bumblebee' group. (replace $USER by your username)
sudo usermod -a -G bumblebee $USER
Reboot or re-login to apply the group changes If you'd like to run a program on the nvidia card now, use the optirun program:
optirun firefox &
Also please look into this thread:
http://ubuntuforums.org/showthread.php?t=2075423
I have not managed to fix the issue but I've found a workaround for output names:
In the kernel boot options, I activate both three VGA connectors:
video=VGA-1:e video=VGA-2:e video=VGA-3:e
In the device section of xorg.conf i define monitor option for all
possible outputs, unrelevant ones are simply ignored:
Option "Monitor-VGA-1" "my-monitor"
Option "Monitor-VGA-2" "my-monitor"
Option "Monitor-VGA-3" "my-monitor"
This is hackish but it solves my main issues.
I still not accept this answer now because I'm interested in a better, cleaner solution.
Best Answer
As far as I can tell from your problem description the correct term for what you want is "hybrid graphics" as you only use either adapter to power your monitor (actually any output), not both at the same time.
An overview over tools for what you want can be found (for example) here. You may be looking for the tool bbswitch from the Bumblebee-Project. Yet, you should not put anything about drivers into your xorg.conf. X should find and load the correct drivers itself. Also, I remember reading something about improved support for hybrid graphics in the most recent stable kernel, so you should get/build the most recent stable kernel for your distro. You may find more on the internet by the term "hybrid graphics" anyways.
Hope that helps.