Now that we’re officially entrenched in the "post-PC" recvolution, we can officially say goodbye to megahertz (and the myths that go along with them) forever. They might still be a necessary evil on Mac spec sheets, but as the iPad and iPhone competitors have proved, the harmony of the package means much more than a top-of-the-line chip.
With Apple released the iPad 2, it was powered by a brand-new processor, dubbed the A5, a customized version of ARM’s Cortex-A9 MPCore dual-core CPU with a dual-core PowerVR SGX543MP2 GPU. What that means is, according to Apple, an iPad that’s twice as fast with graphics nine times faster as its predecessor. The numbers might be a tad skewed by Steve’s Reality Distortion Field, but anyone who used an iPad 2 could certainly see the speed improvements.
With the third-generation iPad, Apple has graduated to an A5X chip, saving the fabled A6 processor for a later revision. It’s a similar dual-core chip (likely at the same clock speed), but it packs a serious punch in the graphics department (hence the "X"), making it four times as fast as the iPad 2’s A5 (or 36 times faster than the original iPad). Calling it a “graphics powerhouse,” senior vice president Phil Schiller not only showed the obligatory slide illustrating its dominance over the iPad 2, but also took the time to compare it to the four-plus-one-core Tegra 3, used to power competitors such as the Asus Eee Pad Transformer Prime, Acer Iconia Tab and HTC One X.
According to Schiller, the A5X’s quad-core GPU bests the Tegra 3’s dodeca-core GPU (that’s 12 for you non-Greek majors) by a factor of 4, putting a severe dent into NVIDIA’s claim as “the world's first mobile super processor.” How is this possible? Two possible reasons: the clock speed of each core (which we don’t know) and the optimization of the OS and software (code needs to be written to take advantage of each and every core in order to see a performance boost). By controlling the whole experience, Apple ensures the a perfect marriage of hardware and software; Asus and Android can’t make the same assurances.
Schiller said the A5X is “designed specifically for the Retina display to drive its 4-times the number of pixels,” and based on the demos we saw on stage, it looks more than up to the task.
