Inside iPad’s brain: the secrets of Apple’s ‘A4’ SoC

The reason that Apple is so secretive about their new “A4” processor that powers iPad, despite habit, it that the “A4 just isn’t anything to write home about,” Jon Stokes reports for Ars Technica.

“The A4 is a 1GHz custom SoC with a single Cortex A8 core and a PowerVR SGX GPU,” Stokes reports. “The fact that A4 uses a single A8 core hasn’t been made public, but I’ve heard from multiple sources who are certain for different reasons that this is indeed the case. (I wish I could be more specific, but I can’t.)”

According to Stokes, “the A4 is quite comparable to the other Cortex A8-based SoCs that are coming onto the market” except that is does away with unneeded I/O hardware.

“So if Apple just licensed the A8 and didn’t design a custom CPU core, then what was the point of the P.A. Semi acquisition? The answer to this question is still unclear,” Stokes reports. “If they were involved at all in the A4 design, and it’s still not 100 percent clear that they were, it’s likely that the P.A. Semi team made its biggest contribution to the A4 in the area of dynamic power optimization.”

“I keep coming back to the idea that Apple has stayed quiet about the A4 because any real magic or “wow factor” that the iPad delivers will come from the software—the efficiency of the OS, the user interface design of the OS and apps, and the snappiness of the overall experience all come from the software team,” Stokes reports. “In this respect, the iPad is actually a lot like the Mac.”

Full article here.


  1. Actually the A4 contains a bunch of trolls who run around inside the chip passing instructions back and forth. I’ve heard that from multiple sources and that’s all I can say for now.

    Wow, I can be a journalist too.

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