The custom-designed A6 core is a big step for Apple, whose previous A4 and A5 processors for iPhones and iPads were based on designs adopted from ARM. The A6 is also based on ARM architecture, but after analyzing code, chip size and the architecture, experts have concluded that Apple has designed its own CPU from the ground up rather than licensing an existing processor design.

It took a few years for Apple to customize its own CPU, but the company wants to control its own destiny, experts said. The new chip gives Apple top-to-bottom control over its smartphones and tablets, and ensures that the CPU and applications perform in tandem while preserving battery life in devices.

Apple will likely continue to custom-design its own CPUs for iPhones, iPads and other devices, the experts said. But Apple will face challenges in a few years as chips get smaller and integrate radios and other components, which may require further investments.

Apple has been quiet on details about the new chip, but has said A6 delivers twice the performance compared to the A5 processor. The iPhone 5 delivers 150 percent more performance than the predecessor 4S, which had an A5 processor based on a Cortex-A9 design, according to iFixit, a computer repair firm that shortly after it was released on Friday morning in Australia.

Anand Shimpi, who runs the tech site , was the first to . He said the new phone is faster than the 4S, but he didn't have many details by Friday afternoon. He plans to publish benchmarking numbers and other details in the coming days.