Graphics card switch on Macbook Pro

So the Macbook pro has two graphics cards, how do I know which one I am using and how do I switch them?

Try this:
gfxCardStatus: menu bar gpu status monitor for os x / cody krieger - mobile, desktop & web developer

You can manually switch them in Energy Saver preferences.

schweb said:

Try this:
gfxCardStatus: menu bar gpu status monitor for os x / cody krieger - mobile, desktop & web developer

You can manually switch them in Energy Saver preferences.

Click to expand...

will it also change when I play a game or something that uses high graphics

That's the theory. But in practice it doesn't work that smoothly.

The best thing is to download the app I linked and control it that way.

What type of Mac are you using? On 2009 and earlier MBPs you had to control it from the control panel - then log out. Luckily gfxcardstatus can swap without having to log out.

On the newer 2010 i5 and i7 MBPs it autoswitches depending on need - or as schweb said, that is the theory. Everything I read says that it tends to stay on the discrete card no matter what.

Anyway, I agree with schweb - the best way to control the card is with gfxcardstatus as you know what card is being used. It runs in your menubar and has a letter corresponding to the graphics card being used. (n for discrete Nvidia i for internal intel) and you don't have to log out to swap it.

So is there any reason to switch other than power-savings?

I didn't know until now that you could switch back and forth. I assumed it's always on nvidia.

Power Savings is the main reason. If you aren't doing anything heavy it really doesn't help to run the discrete card. When I use the internal card, turn down the brightness of the screen, turn off keyboard backlight and bluetooth - I get the ~7 hours of run time reported in my battery meter. With the discrete card the most I've ever got it to report is 4 hours of run time.