Switching between graphics cards

I've just bough an Asus laptop which is equipped with two graphics cards; one integrated in the intel i3 CPU and a Radeon Mobility HD5145.

Will Ubuntu switch between the cards to balance power/performance? I.e. only use the Radeon when the demands placed on the integrated card are too great?

From ubuntu JC Denton

• That sounds like special software or configuration needed. I wonder if tools like http://www.grano.la take that into account.

  From Dmitriy Likhten

• No, Ubuntu will not switch between the cards. This is known as a hybrid graphics system.

  If you look in your /var/log/Xorg.0.log you can see which driver is loaded (page down a few screenfuls and look for RADEON(0) or intel(0).

  The only way I know of to force which card to use is to specify the PCI Bus ID of the graphics card. You get the Bus ID from lspci. It's also usually shown near the top of your /var/log/Xorg.0.log. Then, set up your xorg.conf with a device section and put

  BusID "PCI:0:0:1"
  

  or whatever bus id you want. You don't need to specify the video driver as well (but it can't hurt).

  David Airlie has worked on making hybrid graphics work better. His blog has some interesting info about it... http://airlied.livejournal.com/70348.html

  Googling for 'linux hybrid graphics' may turn up other useful examples and details about it.

  From Bryce

• Right now you can use the GUI provided by Ubuntu Control Center to switch between GPUs, but it only works with the opensource drivers.

  http://code.google.com/p/ucc/

  http://www.omgubuntu.co.uk/2010/08/ubuntu-control-centre-0-5-brings-gpu-switching-to-linux/

  From Benjamim Gois