Discrete VS integrate graphic card
Do you know what discrete card is?
It is… when your pc has 2 graphic cards: one integrated in the chipset while one (the discrete one) is a secondary graphic card.
Example. My notebook has an Intel chips shipped with an integrated graphic card. Notebook manufacturer (Asus) decided that such a graphic card is not enough for the notebook target: high level multimedia taks… so it added an supplementary (discrete) – it is an nvidia in my case – graphic card.
Operating systems (Windows 7) for example have tools to enable and disable discrete graphic card in response to certain events.
Example. Discrete graphic card is active only when defined programs are active.
With my Linux version (Ubuntu 12.04 aka precise pangolin) there no this feature and moreover discrete graphic card is always active… even when on battery and discrete graphic card consumes much more integrated one.
So a way to turn on and off that battery consuming discrete graphic card is welcome.
Solution is in this Ubuntu Community Help Wiki document.
I want to my 2 cents. I have not fully understood that document mainly because tests I did lead to the conclusion that to turn on / off the discrete graphic card it is only needed:
- turn off – echo OFF >/sys/kernel/debug/vgaswitcheroo/switch;
- turn on – echo ON >/sys/kernel/debug/vgaswitcheroo/switch;
to be executed as root of course.
No other commands needed.
Maybe I am doing something wrong but it works. Let me know whether you find the trouble!