Report: iPad's A4 processor features three-layer design

Posted by Aharon Etengoff

A thorough teardown of Apple's iPad has revealed that the once-enigmatic tablet is powered by an ARM A4 processor with a unique, three-layer design.



The three-tiered architecture - which was discovered by iFixit - includes two layers of Samsung RAM and one containing the actual microprocessor.

"That RAM actually exists in two layers within the A4 package, with initial system memory supplied by Samsung. The construction gives Apple the flexibility to change the RAM to any other manufacturer they might choose in the future without remaining locked in to Samsung," explained AppleInsider's Slash Lane.

"Also of note is that the A4 processor does not have a Samsung part number on the die, which is different from previous ARM chips found in every iPhone model thus far."

Indeed, iFixit even declared that it is "perhaps the clearest sign to date that Apple was now in firm control of their semiconductor design."

The iPad's exploratory surgery also turned up a large, dual battery as well as hundreds of thread-like interconnects, known as wirebonds, responsible for transfering electronic signals between dies.