The latest iPad SDK documentation, still in Beta 3, confirms that the iPad comes with Imagination Technologies' PowerVR SGX graphics hardware rather than ARM's own MALI solution.
Apple and Intel have both invested massively in the British startup and have used the licensed IP in their products (Intel in the integrated graphics in their chipsets, Apple in its iPhone and iPod Touch products).
The Cupertino-based firm has only confirmed that the A4 is an ARM-based product that runs at 1GHz. Other than that the documentation says that "Using OpenGL ES on iPad is identical to using OpenGL ES on other iPhone OS devices."
It further adds that "An iPad is a PowerVR SGX device and supports the same basic capabilities as other SGX devices."
Apple has not confirmed which version of the PowerVR SGX has been used but we guess that it is will be the same one that will be present in the iPhone (or next iPod Touch).
Bearing in mind as well that the iPad can display HD content, our hunch points to the Series5XT GPU family.
Apple, we guess, will also be tweaking the PowerVR SGX to bring one of the best power/performance ratio of the industry. If the A4 is anything to go by (especially based on the performance during the launch event earlier this year), we might be in for some interesting surprises.