Xbox 720 Devkit Specs Detailed, Includes 16-Core Processor

[Soleron]

16 cores =/= fast

You could put a few thousand 80386s on a chip and it still wouldn't be fast. I'm guessing each core will not be powerful on its own (comparable to a mobile phone CPU core), and so it will be hard to port from the PC directly. No idea why they would do this.