Hmm, I think someone here has an Xbox 360, which uses a tri core PowerPC derived processor made by IBM. How they can have a tri core processor is a mystery to me as the number of cores usually have to be even numbers.

As for the stuff regarding the binary notation, SMP systems can have cpus in increments of even numbers. They do not have to be 2, 4, 8 and 16. The Sun Enterprise 4500 server has 14 cpus.