Comment: Inside Apple's A4 processor

However, it is widely supposed that a design team that came from Apple's acquisition of P.A. Semiconductor Inc. — known to have ARM design expertise — was given an architectural ARM license to come up with a best-in-class power efficient microprocessor. It is also supposed that result of this two-year gestation is the A4 inside the iPad computer tablet.

Of course the design team may have ignored that ARM architectural license — how ungrateful to the management would that have been — and gone down a different route. There is at least one observer who believes the PA6T-1682M, a dual-core microprocessor based on IBM's Power Architecture is at the heart of the A4 (see markstechchat.blogspot.com), although he concedes that such a core would require the addition of graphics support. But elsewhere it is widely supposed that Apple stuck with an ARM solution, which can readily support the iPhone operating system and applications, which are also a key part of the iPad functionality.

It is also widely supposed that the Apple design team has simply used a Cortex-A8 or A9 dual-core from off ARM's shelf. Some observers have even suggested that a Mali GPU has been used alongside a Cortex A-class core inside the A4 processor instead of something from specialist graphics core provider Imagination Technologies Group plc (Kings Langley).

However, it seems unlikely that Apple management would purchase a crack design team and then be satisfied to see them bolt ARM cores together. Also it seems unlikely that Apple has gone for Mali at this time, given that Apple has used PowerVR graphics cores from Imagination consistently in the iPhone and has also invested in the company, taking its stake to 9.5 percent in June 2009.