When the iPhone 5 was announced, all we knew of its processor was that it was the "Apple A6", but we had no idea what was inside this magical new chip. Apple said it featured "2x faster CPU" and "2x faster graphics", but why and how?

Anandtech is reporting that the A6 is a custom Apple design, saying:

The A6 is the first Apple SoC to use its own ARMv7 based processor design. The CPU core(s) aren't based on a vanilla A9 or A15 design from ARM IP, but instead are something of Apple's own creation.

The benefits of a custom-designed chip from Apple, is that they can tune their processor toward specific goals. These goals could be performance at a certain time while using the phone, or when not in use, some crazy power efficiency. At least we now know that Apple didn't just throw in a Cortex-A15 or A9 chip, but they decided on their own, custom Apple core. It's actually something I hoped was baked into the phone on an article we published yesterday.

Anand himself goes into some amazing detail on his article, and I suggest you check it out.