Why Apple bought PA?

So why did Apple end up paying $278 mil for PA Semi? I read Sramana Mitra's Forbes article on this and also Bob Cringley's post. While both have merits - and Bob's post does make more exciting reading than Sramana's all too simplistic explanation, here's my take on this:

Steve loves to design, more importantly push the limits of design. The one thing he does not control now (in the iPhone and Mac environments - apart from of course the content - think Movies) is the chip design part - and he has to rely on a whole lot of other companies (right from Graphics, Communications to normal processing) to tell him what can be done and what cannot.

Buying PA Semi gives him all the necessary brain power to find out if things can be pushed or not. So if Intel comes back with "It cannot be done this way" or an Infineon (a little exaggeration here) tells Steve that the latest 4G chip will consume X milli watts - Steve can very well extend the limits to what can and cannot be done here....