Editor's note: After conducting a full teardown analysis of Apple Inc.'s iPad mini and iPad 4 tablets shortly after the devices hit the street Nov. 2, engineers from UBM TechInsights put the Apple A6X processor—available for the first time in the iPad 4—under the knife (and microscope).
Inside the new Apple iPad—or iPad 4—lies a modified A6 processor dubbed the A6X. This modified A6 processor still features two application processor cores and operates at 1 GHz. However, the architecture has been modified to include quad-core graphics as opposed to the three-core graphics of the original A6.
At first, we suspected that this new processor would continue to feature the PowerVR SGX543 family GPU. But further analysis found otherwise. From the decap image, right away you can see how the A6X processor is larger in area than its predecessor and the addition of another graphics core accounts for most of that increase.
Side-by-side comparison of die photos of the Apple A6 (left) and the A6X. The original A6 measures 96.5 mm2 in area, while the A6X measures 124 mm2.
A quick comparison of the A6 die to the A6X die shows an increase of 30 percent in die area. These cores are much different in size and shape in comparison to the Apple A6.
According to our sources, the A6X does not use the SGX543MP GPU core of the Apple A6, but instead uses the SGX554. The biggest difference in the SGX543 compared to the SGX554 is that the processor now has twice the compute power via twice as many USSE2 ALU blocks, so A6X doubles the computing power throughput at the same clock compared with the original A6.
Allan Yogasingam is a technical research manager at UBM TechInsights, owned by the same company that publishes EE Times, UBM plc.
Click through the following pages for images from the UBM TechInsights analysis of the Apple A6X.
Fifth GPU core
Apart from the four GPU
cores, there is also a fifth block nearby which is part of the GPU
infrastructure. This block controls the GPU’s largest cache and provides
some other processing required to run the SGX554 cores efficiently.
distinctive die mark also matches that of Samsung-manufactured devices
indicating that, once again, Apple has decided to partner with its
tablet adversary despite the contentious litigation that continues
between both parties.
Click on image to enlarge.
A6X die photo (click on image to enlarge).
Side-by-side comparison of the floorplan of the original A6 (left) and the A6X. A6X floorplan up close
A6X floorplan (click on image to enlarge). Apple A6X (pre-decap)
The pristine Apple A6X prior to being de-capped (click on image to enlarge).