A9X powering the iPad Pro features two CPU cores, 12-cluster GPU with no L3 cacheBy Shawn Knight
There's no question the A9X inside the new iPad Pro is Apple's most powerful chip to date. The fine details of the applications processor, however, have remained a mystery until now as the silicon experts at Chipworks recently shared their A9X findings with The Motley Fool. The results are quite interesting.
A die shot reveals two CPU cores and a 12-cluster GPU. Curiously enough, Imagination Technology - Apple's GPU IP supplier - doesn't list a version of its Series 7XT with 12 shading clusters, suggesting a semi-custom implementation on Apple's part.
Also noteworthy is the fact that the TSMC-built chip is 40 percent larger than the A9 chip found inside the latest batch of iPhones. This not only makes the chip more powerful but also more expensive and harder to manufacture. It's unclear if TSMC is manufacturing each and every A9X or if Apple is relying on a second partner to help meet demand.
Chipworks also discovered that the 8MB of L3 cache found on the A9 isn't present on the A9X die. As the publication explains, the memory interface on the new chip is twice as wide as the one on the A9 which allows data to pass to and from memory twice as fast. This likely negates the need for L3 cache.
Mac Rumors also adds that despite having a higher resolution display, the iPad Pro lacks the 12-megapixel camera found on the iPhone 6s and iPhone 6s Plus that would put additional demands on memory.