Yesterday I theorized that Apple would be using its first in-house computing architecture for the just announced Apple iPad (tablet device) after learning that Apple was definitely NOT using the NVIDIA Tegra technology.  Well that did in fact come to pass:

Apple develops its first CPU: the Apple A4 - Processors 3
Image from

What do we know about the processor other than it runs at 1.0 GHz and is based on the proprietary technology Apple purchased with PA Semiconductor in April of 2008?  Not much.  PA Semi was previously known for its own design of CPU called the PWRficient processor and while we don’t know how much of that was worked into the Apple A4, we have to assume a lot.  It would seem unlikely that in a time span as short as a year and half Apple’s new team would have been able to make a completely custom design; though anything is possible.

A lot of rumors are circulating, including one from the guys at, saying that the A4 is a new ARM-based design, but I haven’t heard anything to corroborate this.  (UPDATE: sent me to this link which seems to indicate that PA Semi was a “secret” licensee of the ARM processing technology.  If this is the case, how different can the A4 be than other ARM-based designs?) In my research, PA Semi wasn’t know for utilizing ARM designs at all.  They also were able to spy a shot of the chip:

Apple develops its first CPU: the Apple A4 - Processors 4
Image from iFixIt.comProcessor markings: 1SB009A 0940; H8M8T00V0MTR-OEM; VTJK00782

There isn’t much else we can learn from the chip or the design from this picture other than the one used for this photo was manufactured in September of 2009.  We’ll be sure to let our readers know as more information is revealed!