Certainly, but Apple code also run on x86. My main point actually is that Apple don't pick this route for the fun of it. It HAS a need to be performant on mobi

Certainly, but Apple code also run on x86. My main point actually is that Apple don't pick this route for the fun of it. It HAS a need to be performant on mobiles devices (that have less luxury to get a GC that eat Ram) and that need represent A LOT OF MONEY. You can say any step about this, including making processors, are directly or indirectly related to the need. P.D: I don't see Rc VS Gc as enemies, but as faces of the same coin. ARC is just a way to apply some Gc lessons to naive Rc. I think naive Rc is truly worse than Gc, but smart Rc is total fine and consider it the best of both in the general case...