Apple was quick to obsolete the "new" chip in the third-generation Retina iPad -- not to mention the iPad itself. So the question is, why so fast?
But before we answer that question, let's look at some of the improvements. Apple says the A6X "delivers up to twice the CPU [central processing unit] and graphics performance of the A5X chip" -- the A5X being the processor Apple just announced back in March when it rolled out the first Retina iPad.
A lot of that improvement comes from the goodness of Apple's new A6 chip design, according to Anand Shimpi of Anandtech. "The 2X performance [improvement] on the CPU side points to the same move [as the iPhone 5] to Apple's own design," he said in an e-mail.
In other words, the A6/A6X is the first design Apple can truly call its own -- or what Anand calls "Apple's first fully custom" chip.
[The A6] appears to offer better power/performance efficiency than any other currently available ARM [chip]...Its architecture, performance, and power profile most closely resemble Qualcomm's 28nm Krait/Snapdragon S4, although through hardware or software optimizations it appears to be able to come out slightly ahead. --Anand Shimpi
And the A6X is an even faster version of the iPhone 5's A6. Some of that extra performance comes from the quad-core graphics silicon -- which the iPhone 5's A6 doesn't have (the A6 has three graphics cores, according to Anandtech).
And Anand speculates that processor cores are running at higher frequencies too, compared with the A6.
Which raises the question, what's the hurry? The fourth-generation iPad wasn't supposed to show up until March 2013.
"I think there's some serious buzz kill going on here, with Microsoft's [Windows 8] announcement coming later this week," said Richard Shim of DisplaySearch, speculating that Apple may be trying to bury Microsoft's announcement under a mountain of iPad, MacBook, and iMac announcements.
And in the case of the iPad, it behooves Apple to get the latest and greatest tech into the flagship iPad now, making it that much harder for Microsoft (and, let's throw in Google too) to one up Apple with their tablet tech.
More specifically, Apple wants to get the same high-performance A6 chip technology that's in the iPhone 5 into a new iPad, pronto.
Sorry, prospective iPad Mini owners, but the A5 is so yesterday.