The iPad mini arrived in earnest this past weekend and it of course did not take long for it to be disemboweled, its innards hung out for the world, or at least geek world, to see. We already knew it was powered by an A5 so an open question was whether Apple’s long rumoured move to another foundry partner was underway. So what does the reverse engineering tell us. Chipworks told us that the A5 of the iPad mini is the same “shrink” version that appeared earlier this year in the Apple TV3 and iPad2. Chipworks then presents cross-sectional evidence to support the A5 being from the same 32 nm Samsung process. One thing to note is the A5 die photo in this article is the same photo from the original A5 shrink sighting. One sees the two identical darker blobs or hazy bits on the die. Moving on it is, however, with the A5 itself that there are subtleties worth discussing.
During the Apple TV3 announcement, the A5 powering it was presented as “Single Core.” In the subsequent reverse engineering it was found there were in fact two CPU cores. At this point the concept of binning was put forward. We posted our own thoughts on this find, discussing the role marketing might play. Fast forward to October 23rd and Apple introduced the iPad mini as being powered by a “Dual Core A5”. Now we are back where this article started. The A5 “Single Core” is the same as the A5 “Dual Core.” Yes the binning theory could still hold but, it is far more likely there is a fair dose of marketing here. One could differentiate the same A5s according to the use of the processing resources when those resources are the same. So the same number of cores, but a “new” IC when a greater number of those resources are being accessed by the system hardware and software. It is just a thought.