Skip to content or navigation

Apple’s A4 chip could be Quadcore – Cortex A9 based

Apple’s A4 chip is possibly more interesting than the iPad itself. In this article we explain a bit why


Like many others yesterday’s iPad announcement really had two exciting elements: the new iPad and the Apple-designed main processor, the A4, inside it. In some ways the A4 is a bit more exciting but I am sure Mr. Jobs doesn’t want us to see it that way. But we do, and for good reason: Apple has designed its first important main CPU and that is just plain exciting.

The A4

It is exciting for a couple of key reasons. Firstly, Apple bought PA Semiconductor a few years back and that group consisted of a “dream-team” of microprocessor designers. If you follow the PA Semi tag at the bottom of this story you can find some stories that will allow you to learn the details of PA Semi and who the group was. So with chip “dream team” in hand what would Apple do with that expertise? The obvious answer is create amazing processors that distinguish things like the iPad from rival products.  So the A4 is exciting because it is the first “child” from the PS Semi team.

The second reason it is exciting is because this first chip begs the question: what other future custom Apple chips are in the works? And what products may they go in? In particular, will the A4 go into the next version of the iPhone itself?

You see when you buy a “dream team,” then hide them away and come out with secret chips like the A4 and share absolutely no detail about its inner workings you create amazing drama. Period.

Sorry Steve if we are so darn excited about the A4 that we don’t seem to be focused solely on the iPad itself…but what do you expect?

The Secrecy

I actually applaud Apple for keeping the A4 so secret, even though it is personally killing me not to know the details. It’s just another fork of interest that will drive the media’s vectors back in the direction of the new iPad. Again, secrecy scores a point for Apple.

However, maybe the secrecy is because the A4 isn’t so custom after all? Perhaps it is simply an ARM Cortex A9-based multicore chip that happens to be quadcore. Does that sounds plausible? It does to me after reading up on ARM’s latest and greatest.

Apple has a somewhat unique and premium-class license with ARM which came by way of its PA Semi acquisition. Basically they can highly manipulate ARM chip architectures rather than simply package custom chips around ARM chip architectural modules. I suspect given the time Apple has had PA Semi that this first A4 chip is not as customized as Apple could eventually make it. But here are some basics that might exist in the A4 now:

A4 Possible and Known Internals:

  • ARM Cortex A9-based architecture, modified by Apple
  • Quadcore (?)
  • 1 Ghz main frequency
  • 2 MB L2 Cache
  • 45 nanometer process
  • 300 milliwatt max power use
  • ARM NEON Processing Media Engine (?)

That’s the shortlist. Some of this we know and some of this we may not know for quite some time. You can see some pictures in this article from yesterday. Check them out, one is of the ARM Cortex A9 architecture. Write us or comment below. We’d appreciate your thoughts.