I'm experiencing a major problem with a fresh install of Starcraft 2 on a brand new MBA 13" i5 256GB, and am wondering what other people's experiences are: What I'm seeing is a major CPU load that does not seem to relate to the FPS. It's there at login, it's there at the menu screen, it's noticeable in 1v1 games, it's noticeable in windowed mode, in 1152x768 and in 1440x900. The fan spins to 6500rpm, due to a stressed CPU. Here the stats from iStat Menus: 20% login screen, running windowed 22% menu screen, running windowed 28% in 1v1 game vs AI right after launch Interestingly it's always two cores that have heavy load and two cores that don't do anything. SC2 seems to not be optimized for more than two (hyper-)cores. For these tests I've lowered the max frames/sec settings in variables.txt to 16 using frameratecap=16 and frameratecapGlue=16. Removing these values increases the CPU load in game. All other graphic settings are the "recommended" settings, aka 1152x768, medium textures and medium graphics. Using the lowest settings does not help either. As the CPU load is not related to the graphics, it's probably some other code that has a problem with either the MBA2011 or Lion. I'd guess it's a tiny subroutine going nuts. As even a 20% CPU load when idling cause the fans to spin up to max, I'm unsure if it's a good idea to play SC2 for a long time. Or is it just my installation and you're seeing less than 20% CPU load when idling?