Xbox 360 was the first Xbox console to use a dedicated three-core processor.
The Xbox 360 used a custom IBM PowerPC-based CPU known as Xenon. It contained three symmetrical processing cores, each capable of running two hardware threads, giving developers six hardware threads to schedule. Microsoft designed the processor with IBM and used it as a major part of the console’s performance strategy.
This architecture differed from the original Xbox, whose main processor was a single-core Intel Pentium III-based chip. The Xbox 360’s three-core design helped support more complex physics, artificial intelligence, animation, and online game systems, although developers had to learn how to distribute workloads effectively.
The console launched in November 2005 and used a separate ATI graphics processor. Later Xbox consoles moved to x86-64 CPU designs based on AMD technology, so the Xenon processor is particularly associated with the Xbox 360 generation. The term “three-core” refers to CPU cores, not the number of processors in the entire console.