Infrared microscope inspection of Apple's new A5X processor revealed that the chip was designed and built around Samsung's 45nm low power architecture, which is currently used in A5 processor found in the iPhone 4S and iPad 2.



From AppleInsider:

As part of its comprehensive component-by-component analysis of the third-generation iPad, Chipworks has discovered that Apple's new A5X processor is being manufactured using Samsung 45nm CMOS process.

Measurements of the connected gates taken during cross-section analysis of the A5X confirm that it is a 45nm chip, similar in architecture to Apple's previous generation A4 and A5 silicon.

  iPad A5X processor built on Samsung's 45nm technology