This system has nvidia optimus techonology enabled. Nvidia driver doesn't support optimus in linux. So in linux both graphics card are on which lead to high battery consumption and overheat.

In optimus tech, the intel graphics is always on. When you use Nvidia 540m, images generated by GT540m actully transported through intel grphics card.

options available

Turn off nvidia 540m and use intel only. Use Nvidia card with special command only when required. Also never install nvidia-drivers alone.

Instruction for installing Bumblebee to turn off discrete GPU and enable only when required

1. Type the following in terminal,

   
   
   

   sudo add-apt-repository ppa:bumblebee/stable

   
   
   

   then

   
   
   

   sudo apt-get update




2. To install Bumblebee using the proprietary nvidia driver:

   
   
   

   sudo apt-get install bumblebee bumblebee-nvidia




3. Run following

   
   
   

   sudo usermod -a -G bumblebee $USER




4. Reboot.

If you just want to disable nvidia card, no need to learn followings

Usage Instruction :

To run a program with nvidia card, use optirun command prefixed in terminal.
Like to run glxspheres with nvidia card type

optirun glxspheres

To run firefox type : optirun firefox &

Note: If you intend to run 32-bit programs like Wine and using Ubuntu 11.10 Oneiric or later, install 32-bit libraries with:

sudo apt-get install virtualgl-libs:i386 libgl1-mesa-glx:i386 libc6:i386

Linked Questions:

How well will Nvidia Optimus cards be supported in 12.04?

Is a NVIDIA GeForce with Optimus Technology supported by Ubuntu?

Can't use nvidia card/driver on optimus notebook