When Apple first debuted the new 1080p Apple TV in March, they said they’d brought their set-top box up to spec with the rest of the industry by including what they called a “single-core variant” of the iPad 2 and iPhone 4S’s A5 processor.
But how is it an A5 processor if only has one core? The answer is that technically, the A5 inside the Apple TV is still a dual-core chip, but one of them’s a dud.
Either Apple is only utilizing one core or they are binning parts. Parts binning is a common process in semiconductors where devices are segregated (binned) based on meeting a subset of the overall requirements, in this case they could disable the “bad” core, this increases the usable die per wafer, lowering the cost.
Very simplistically, this means that Apple may be reusing A5 dual-cores that were meant to go on a chip going into the iPad 2 or iPhone 4S, but which was found to have one core faulty or damaged. They just disable that core and slap it into a system-on-chip. This allows them to use A5 components they might otherwise have thrown in the trash.
As for the SoC itself, it’s 41% smaller than an A5 inside an iPad 2 or iPhone 4S, mostly to save Apple money, since using a smaller nanometer process makes chips cheaper to produce.
So don’t look at the new Apple TV and just see some warmed-over leftovers of year-old tech: the new Apple TV may be frugal, but it’s doing some sexy new things.