The new MacBook Pros ship with two graphics cards: the NVIDIA 9600M GT for games and high-performance tasks and the NVIDIA 9400M for power savings. Seems pretty sweet, right? Plug your laptop in and run with a great mobile GPU, unplug it and you've got long battery life.
Wednesday, October 15, 2008
But wait. Switching cards isn't automagic. It's not even just a change in preferences.
As this support page explains, you need to log out!
Think about that. Nobody obsesses about user-experience like Apple. Love 'em or hate 'em, every element of using an Apple product, from unboxing on, has been debated, argued, and considered. Think Steve said "The best user-experience is to have to log out, ensuring that you often have accidentally left the laptop in high performance mode as you get on a cross-country flight. Perfect!"
Unlikely. So why didn't they? Because an army of engineers at two very smart companies -- Apple and NVIDIA -- were unable to ensure switching cards wouldn't cause horrible lockups and system crashes without a full log out. Switching on the fly would leave dynamic libraries incorrectly bound, state set incorrectly, or whatever underlying problem forced them into a suboptimal user-experience.
Hopefully as more laptops go to heterogeneous GPU setups these kinds will be worked out, but it's yet another reminder of how difficult it is to get high-performance 3d just right.
Even a decade after GPUs started going mainstream.