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XCPU-ES Xenon.jpg
Xbox 360 Engineering Sample XCPU
Type Internal/Beta/Retail
Purpose Central Processing Unit
Rarity Common

The Microsoft XCPU is the CPU used in all Xbox 360 board revisions. It is based on IBM's PowerPC instruction set architecture. The XCPU contains 3 processor cores with each supporting two symmetric hardware threads. Each core has 32KiB of L1 instruction cache and 32KiB of L1 data cache.

The XCPU was developed by Microsoft and IBM under the project codenamed "Waternoose" (from Henry J. Waternoose III in Monsters, Inc.) Its development was announced on 2003-11-03.



The Xbox 360 S introduced the XCGPU, which integrated the Xenon CPU and the Xenos GPU onto the same die, and the eDRAM into the same package. The XCGPU follows the trend started with the integrated EE+GS in PlayStation 2 Slimline, combining CPU, GPU, memory controllers and IO in a single cost-reduced chip. It also contains a "front side bus replacement block" that connects the CPU and GPU internally in exactly the same manner as the front side bus would have done when the CPU and GPU were separate chips, so that the XCGPU doesn't change the hardware characteristics of the Xbox 360.

XCGPU contains 372 million transistors and is manufactured by GlobalFoundries on a 45 nm process. Compared to the original chipset in the Xbox 360 the combined power requirements are reduced by 60% and the physical chip area by 50%.[1][2]



  1. Jon Stokes, Ars Technica (August 24, 2010). Microsoft beats Intel, AMD to market with CPU/GPU combo chip. Retrieved on August 24, 2010.
  2. PC Perspective (June 21, 2010). The New Xbox 360 S "Slim" Teardown: Opened and Tested. Archived from the original on June 25, 2010. Retrieved on June 24, 2010.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Jeffrey Brown (December 6, 2005). Application-customized CPU design: The Microsoft Xbox 360 CPU story. Archived from the original on October 25, 2007. Retrieved on September 8, 2007.
  4. César A. Berardini (August 21, 2006). Chartered to Manufacture 65-nm Xbox 360 CPUs. Archived from the original on January 23, 2008. Retrieved on January 9, 2008.
  5. Patel, Nilay (June 14, 2010). New Xbox 360 looks angular and Ominous. Engadget.com. Retrieved on June 14, 2010.
  6. 6.0 6.1 Xbox360 security system.