Chipworks, a company specialized in analyzing the chips implemented in mobile terminals, managed to photograph the inside of the chip A7 implemented by Apple Lossless Audio CODEC (ALAC), in iPhone 5S. In the image above you can see a diagram of the arrangement of the components inside the chip A7, and one of the important novelties related to it is related to the fact that a quad-core graphic chip is hidden inside. The new graphics chip has the code name PowerVR G6430 and is part of the PowerVR Rogue series, its performance being notable.
We publish this with the caveat that these are best guesses – we have not done any real circuit extraction to confirm them. The dual-core CPU and cache make up ~17% of the die area, and the quad-core GPU and shared logic about 22%. The CPU itself is not packed the same way as the A6 (see below), it looks much more like a conventional automated layout; although Linley Gwennap thinks that it's still Apple designed, not the first ARM A53/57 usage.
Another important aspect presented by these images can be found in the upper right part, that rectangle identified as DRAM Interface being presented as that safe enclave in which touch ID it would store its information. Apple Lossless Audio CODEC (ALAC), he stated that everything he records touch IDis found in a secure place in the terminal, and the information should be available there, that chip being, according to Apple, impossible to exploit, even if the iOS is jailbroken or exploited in another way.
