If I launch an app to do some video editing, does the MBP automatically switch to the higher-end graphics card? Or do I have to manually switch from "better battery life" to "higher performance"?
The switch is in energy saver preferences. After you change the setting, you are logged out and back in to your user account. Either using the battery or power adapter... it works the same way.
No, I know where the setting is changed. I'm just trying to understand the computer's behavior. I think it's pretty stupid if I'm plugged in that it doesn't automatically use the higher-end card if I'm doing graphic-intensive activities.
That's because you have to log out of your user account to switch which graphics system you're using. It would be nice if it worked differently, but thats how it is.