Further analysis by AnandTech showed that initial guesses as to the GPU specification of the Apple A8X chip, exclusively available in the iPad Air 2, were wrong. In fact, the chip uses a unique 8 cluster design. AnandTech describes the discovery as “even better than I thought”. Although the customizations are limited, this represents a big step for the company as it is now dabbling in both custom CPU and GPU engineering, even if the leap over generally-available components in this instance is small.
Apple has come up with a way to stick two Imagination GX6450 PowerVR chips on the same die. While AnandTech was not able to publish the die shot that confirms this, the shot shown above is a mockup of the internal layout.
Apple’s license for PowerVR GPU cores allows it to modify the Imagination designs to fit its needs. AnandTech notes that in this case it appears that Apple has taken the GX6450 design and created a new design from it, culminating in an 8 cluster Series6XT design.
Hopefully, this indicates that Apple will continue to be aggressive with future GPU designs. The A8X’s design, which included 2GB of RAM, showed a healthy leap forward from previous designs.