Sprite size limit? - iPhone

Is there a general rule regarding the limit of size of an animated sprite on the iPhone? For example, is a 2048x2048 image yielding 64 256x256 frames too large. Could the engine handle 256 images from a 4096 source? What sprite frame rate could the engine handle running two 256 animations at once? I'm coming at this from an After Effects animator point of view so I'm trying to figure out how to get the most fluid animation in TGB. If this is common knowledge, sorry about cluttering the forums, I can't seem to find this info anywhere. Thanks!
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Dave