Xbox Solution - Inside the Xbox 360 Xenon CPU

"The Xenon's triple-core design shares some DNA with the Playstation 3's Cell processor, so it's not surprising that it also embodies many of the same assumptions about the best way to wring performance out of the sorts of extremely large transistor counts that Moore's Curves have given the latest generation of integrated circuits. Like the Cell processor that will power the Playstation 3, the Xenon carries on the "RISC"-style tradition of trading programmer/compiler effort for hardware. In a nutshell, software writers who develop for Xenon must take on more of the burden of optimizing their code by making it explicitly parallel, and in return they get more execution hardware to play with."

Xbox Solution - Inside the Xbox 360 Xenon CPU