A different FPS cap per device generation?

The 3GS and older is struggling to handle the game now at 60fps, but its fine at 30fps. Where as iphone 4 and upwards still runs smoothly at 60fps. So if possible I’d like set the kFPS in AppController.mm to be conditional based on the generation somehow. Does anyone know of a way?

i got this with a quick google search

http://stackoverflow.com/questions/1108859/detect-the-specific-iphone-ipod-touch-model

http://stackoverflow.com/questions/448162/determine-device-iphone-ipod-touch-with-iphone-sdk