I read somewhere that the framerate on ios is locked to either 60, 30, or 20 FPS.

So the default mmf 50fps does actually only run on 30fps but still calculates events etc on the other 20? or does it run on 60fps and skips calculation on 10 of them?

On Hungry Fish i reduced the framerate to 30fps and it really improved performance.

Now i am playing a bit with a new game that shouldn't take to much memory and with fast movements, should i choose 60fps? is this the highest and optimal framerate for ios devices?