As part of their iPhone 5 announcement, Apple revealed that the new iPhone is powered by a new "A6" processor from Apple. The A6 is said to have twice the CPU power and twice the GPU power of the previous generation Apple A5 processor. Beyond that, however, Apple offered few other details about the nature of the processor. For example, it's not clear how many cores the processor has or what the clock speed is.
[Source: MacRumors - Read more here]