Xenon (processor)
 IBM Xenon microprocessor. | |
| General information | |
|---|---|
| Designed by | IBM |
| Common manufacturer | |
| Cache | |
| L1 cache | 32/32 kB |
| L2 cache | 1 MB |
| Architecture and classification | |
| Instruction set | Power Architecture |
| Physical specifications | |
| Cores |
|
| POWER, PowerPC, and Power ISA architectures |
|---|
| NXP (formerly Freescale and Motorola) |
| IBM |
|
| IBM/Nintendo |
| Other |
| Related links |
| Cancelled in gray, historic in italic |
Xenon is a CPU that is used in the Xbox 360 game console. The processor, internally codenamed "Waternoose" by IBM[1] and XCPU by Microsoft, is based on IBM's PowerPC instruction set architecture, consisting of three independent processor cores on a single die. These cores are slightly modified versions of the PPE in the Cell processor which was designed specifically for the PlayStation 3.[2][3] Each core has two symmetric hardware threads (SMT), for a total of six hardware threads available to games. Each individual core also includes 32 KiB of L1 instruction cache and 32 KiB of L1 data cache.
The processors are labelled "XCPU" on the packaging and are manufactured by Chartered (now part of GlobalFoundries). Chartered reduced the fabrication process in 2007 to 65 nm, thus reducing manufacturing costs for Microsoft.
The name "Xenon" was repurposed from the code name for the Xbox 360 in early development.
Specifications
- 90 nm process,[4] 65 nm process upgrade in 2007[5] (codenamed "Falcon"), 45 nm process since Xbox 360 S model[6]
- 165 million transistors
- Three symmetrical cores, each two way SMT-capable and clocked at 3.2 GHz[4]
- SIMD: VMX128 with 2× (128×128 bit) register files for each core[4]
- 1 MB L2 cache[4] (lockable by the GPU) running at half-speed (1.6 GHz) with a 256-bit bus
- 51.2 gigabytes per second of L2 memory bandwidth (256 bit × 1600 MHz)
- 21.6 GB/s front-side bus[4]
- Dot product performance: 9.6 billion per second
- 96.0 (4× 32VMX + 1× FPU × 3 cores × 3.2 GHz) GFLOPS theoretical peak performance (single-precision)[4]
- 57.6 (2× 64VMX + 1× FPU × 3 cores × 3.2 GHz) GFLOPS theoretical peak performance (double-precision)[4]
- Restricted to in-order code execution[4]
- eFuse 768 bits[7]
- ROM (and 64 kbytes SRAM) storing Microsoft's Secure Bootloader, and encryption hypervisor[7]
- Big endian architecture
XCGPU
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 is the first mass marketed chip that combines a desktop class CPU, a powerful GPU, memory controllers and IO. 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%.[8][9]
References
- ^ "Learning from failure - The inside story on how IBM out-foxed Intel with the Xbox 360", Dean Takahashi, Electronic Business, May 1, 2006
- ^ "Processing The Truth: An Interview With David Shippy", Leigh Alexander, Gamasutra, January 16, 2009
- ^ "Playing the Fool", Jonathan V. Last, Wall Street Journal, December 30, 2008
- ^ a b c d e f g h Jeffrey Brown (2005-12-06). "Application-customized CPU design: The Microsoft Xbox 360 CPU story". Retrieved 2007-09-08.
- ^ César A. Berardini (2006-08-21). "Chartered to Manufacture 65-nm Xbox 360 CPUs". Retrieved 2008-01-09.
- ^ Patel, Nilay (14). "New Xbox 360 looks angular and Ominous" (HTML). Engadget.com. Retrieved 2010-06-14.
{{cite web}}: Check date values in:|date=and|year=/|date=mismatch (help); Unknown parameter|month=ignored (help) - ^ a b "Xbox360 security system". Cite error: The named reference "google" was defined multiple times with different content (see the help page).
- ^ Jon Stokes, Ars Technica (2010-08-24). "Microsoft beats Intel, AMD to market with CPU/GPU combo chip". Retrieved 2010-08-24.
- ^ PC Perspective (2010-06-21). "The New Xbox 360 S "Slim" Teardown: Opened and Tested". Retrieved 2010-06-24.
- Xenon hardware overview by Pete Isensee, Development Lead, Xbox Advanced Technology Group, written some time before 23 June 2004
External links
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