IBM Debuts Xbox 360 ProcessorSAN JOSE, Calif.—Attendees at the In-Stat Fall Processor Forum here Tuesday got a preview of the of the custom-designed processor that will power Microsoft Corp.s next-generation Xbox 360 game console. The CPU comprises three 64-bit PowerPC cores, each running at 3.2GHz, "the highest core speed" ever achieved by this technology, according to Jeff Brown, IBMs chief engineer for the Microsoft CPU Project. Able to support two simultaneous threads, the processor was designed with the key goal of being able to support the high sustained bandwidth required by the game console. Brown said the processor should be able to hit a peak bandwidth of 21.6G bps. "Microsoft engineers were involved in every step" of the design process for the chip, which has a name that Brown declined to reveal during his presentation. The processor will also feature a split L2 cache, with the first part running at the same frequency as the CPU, while the other will run at half that. Brown also declined to disclose the processors power and heat numbers. The chip, which is based on IBMs 90-nanometer Silicon on Insulator (SoI) technology, is being constructed at IBMs own Fishkill, N.Y., plant and at Singapore-based Chartered Semiconductor. Although the new processor will feature 128 registers, the first 32 will be mapped to the 32 registers available in the previous generation of processors, Brown said. This will contribute to the processors binary compatibility with a subset of the standard PowerPC architecture, he said. The move from first silicon to a working prototype of an Xbox 360 took only eight months, Brown said. This factor will enable systems to go on sale Nov. 22, he said.