Silicon analysts over at Chipworks were able to conclude yesterday that the smaller A5 package, which was recently discovered inside a retooled Apple TV, is still being fabbed on Samsung’s 32-nanometer process rather than on TSMC's 28-nanometer technology, as some watchers speculate. Compared to its 2012 counterpart, the new A5 with a 2013 die is noticeably smaller, prompting questions on how Apple has managed to achieve a smaller die without changing fabbing technology.
The full A5 floorplan Chipworks published this morning reveals the culprit: the new die is smaller because the package contains just one ARM CPU core. Now, Apple has always rated the Apple TV as single-core, but previous implementations called for dual-core designs with one core intentionally disabled, though still present.
In removing one CPU core altogether, Apple's silicon team was able to shrink the die size without having to switch to a more sophisticated fabbing process technology...