Chipworks’ teardown of the new Apple TV and the new iPad 2 (that’s now available for $399) revealed that both these devices now have a tweaked A5 chip, which is manufactured using 32-nm process as compared to the older A5 chip’s 45 nm process.
In addition to the reduced die size, the teardown also reveals that the A5 chip that powers Apple TV 3, although advertised as single core, is in fact a dual core chip with one core disabled:
The new A5 processor die is not a single core processor, but contains a dual core processor. 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.
Apple reflects this change in its internal naming as well. The $399 iPad 2 is internally referred to as the iPad2,4 and not the iPad2,1.
This suggests that Apple is using the Apple TV and the $399 iPad 2 as a testing ground for the newer 32nm process. Since both these devices are not expected to sell as much as the iPhone 4S or the new iPad, there’s not a lot of pressure on the manufacturing process to churn out a huge number of chips. Moreover, chips with a faulty core could be used in Apple TV 3 as it anyways ships with one core disabled.
The dual cores in the iPhone 4S A5 and on the Apple TV A5
The smaller chips helps Apple reduce manufacturing costs and improve performance and battery life. While the former won’t mean much to the consumer, improvement in battery life and performance would surely be appreciated.