Powering Apple's largest, most powerful tablet ever is also the company's largest, most powerful chip ever, too.

Apple's iPad Pro has been long around enough for reviewers to put the device through its paces. The Cupertino company's professional-grade tablet is in fact powerful enough to keep up with some i7-powered Macbook Pros when exporting 4K video.

All that power begins in Apple's new A9X chipset. The original A9 powers the iPhone 6 and 6s allowing those devices to have a buttery-smooth performance and compete even against higher spec'd Android devices. The A9X builds on that, primarily in size.

"Driving its high level of performance is the powerful A9X chip. It was specifically designed for iPad Pro, and to meet the demands of a much larger display. Its size lets you do and see more," says Jony Ive in the iPad Pro's introductory video.

Because of the iPad Pro's sheer size, Apple had the opportunity to build an equally larger A9 chipset. As a result of the extra legroom in the device, the A9X measures 146 square millimeters, or nearly 0.23 square inches - 40 percent larger than the size of the A9 chip inside the iPhone 6s and iPhone 6s Plus.

To Apple's credit, it's quite the feat to pull off since an increase in area also means an increase in transistor count, which is doubly more difficult to make, especially for the first time on a new device using fairly new manufacturing technology.

In the teardown conducted on the A9X, it was observed that the chipset contains a 12-cluster GPU, two CPU cores, and an absence of level-three cache memory that was found inside the A9 chip. It seems that Apple's custom 12-cluster design on the A9X is built on what they had previously done in last year's A8X chip. As for the lack of on-die cache memory?

"The A9X features a memory interface that's twice as wide as the one on the A9, allowing the chip to pass data to and from memory at twice the rate that the A9 can," notes Dick James, Chipworks' teardown contact.

Thanks to the iPad Pro's size, and of course, Apple's engineering prowess, the A9X is the most powerful mobile chip today and that should keep both customers and investors happy.