David Airlie has posted a video (low quality) that shows the process of GPU switching he has been coding in the past 4 days. It basically shows how one would switch on the discrete graphics card through a terminal command, although this could have a simple graphical menu like OSX. Then, after the log-out and login, the discrete graphics card is in use.
http://airlied.livejournal.com/71012.html
Windows 7
Windows 7 does this seamlessly, although the level of functionality varies from laptop to laptop. For some laptops, you need to close certain applications before doing the switch. For example, if you are running the discrete graphics card and playing a game that uses 3D acceleration, you cannot simply switch if off and keep playing. You need to exit the game, then switch the card off. Otherwise, it crashes.
It is not a problem to leave non-3D accelerated applications or background applications open though, which is why it doesn't require the log-out/login mechanism like Apple's OSX. Right now, Apple is only providing a hybrid graphics configuration for the high end MacBook Pro line (15 and 17? inch MBPs). The 13 inch MacBook only has an integrated nvidia 9400 chipset, which is why people with this laptop see some lag in graphical applications like Keynote slide editing and so on. The nvidia 9400 integrated chipset is not so different to an integrated Intel GMA chipset, so some 3D-intense jobs suffer from the lack of power.
http://airlied.livejournal.com/71012.html
Windows 7
Windows 7 does this seamlessly, although the level of functionality varies from laptop to laptop. For some laptops, you need to close certain applications before doing the switch. For example, if you are running the discrete graphics card and playing a game that uses 3D acceleration, you cannot simply switch if off and keep playing. You need to exit the game, then switch the card off. Otherwise, it crashes.
It is not a problem to leave non-3D accelerated applications or background applications open though, which is why it doesn't require the log-out/login mechanism like Apple's OSX. Right now, Apple is only providing a hybrid graphics configuration for the high end MacBook Pro line (15 and 17? inch MBPs). The 13 inch MacBook only has an integrated nvidia 9400 chipset, which is why people with this laptop see some lag in graphical applications like Keynote slide editing and so on. The nvidia 9400 integrated chipset is not so different to an integrated Intel GMA chipset, so some 3D-intense jobs suffer from the lack of power.