Powering the new iPhone 5s is a new piece of silicon from Apple – the A7 processor. While Apple tells us that it is twice as fast as the A6, that doesn't really tell us much about what's going on inside it. To help lift the lid on what's going on inside it, repair firm iFixit, in association with Chipworks, have been busy taking it apart and examining it under an electron microscope.
Apple already told us that the A7's die is 102 mm2 and that they've managed to pack into that space 1 billion transistors. This is impressive, but the teardown to the processor has revealed some very interesting stuff.
First we found that the A7, jsut like it's older siblings,. The two companies may be locked in fierce patent battles that encircle the globe, but that doesn't stop the two companies from working together.
We also find that the A7's "gate pitch" — that is, the distance between each transistor on the die — has shrunk to 114-nanometers, compared to the A6's 123-nanometers. That might not seem like much but it allows Apple to squeeze more compute power into a smaller space – 77 percent of the original to be precise.
Another interesting discovery is the fact that Apple's A7 processor is built using the same 28-nanometer process as Samsung's eight-core Exynos 5410, the flagship CPU used in the Galaxy range. Which ironically means that Apple is benefitting from Samsung's attempt to stay ahead of the iPhone.
There's also been some more development on the M7 coprocessor front (theof the iPhone 5s). While Apple tried to make out that this was something unique, going as far as branding it M7, it is in fact an off the shelf component. It is an NXP LPC18A1, one of the LPC1800 series of high-performing ARM Cortex-M3 based microcontrollers. It is the same silicon used in the Oculus Rift gaming platform.
Chipworks also too at look at the new iSight camera sensor, and confirmed that the pixel pitch has been increased to 1.5-microns. This, combined with the wider f/2.2 aperture and a 15 percent increase in overall sensor size will mean better low-light performance from the camera.