http://www.engadget.com/2010/01/28/apples-a4-is-an-arm-based-system-on-a-chip-a-la-tegra-2/#comments There was a lot of speculation about how it was probably a special 64 bit PA Semi PA6T based processor. It isn't. It isn't particularly "custom" either. It's a Cortex A9 and a Mali GPU. Compare it with the Tegra 2, which contains dual Cortex A9s, and their custom GPU. Snapdragon is based off of the Scorpion, which is basically a Cortex A8, with an AMD Z430 GPU. So, people yesterday were talking about how the chip is going to "scream", dominate benchmarks, etc. Well, not quite. It will edge out Snapdragon and it's older Cortex A8 based architecture, but will be roundly beaten by the Tegra2, which contains more than double the power.