Xenos (GPU)

Xenos is a custom graphics processing unit (GPU) designed by ATI, used in the Xbox 360. Developed under the codename "C1," it is in many ways related to the R500 desktop PC graphics card series and therefore very similar to an ATI Radeon X1900 as far as features and performance are concerned. However, the Xenos introduced many new design ideas that were later adopted in the R600 series. The package contains two separate silicon dies, the GPU and an eDRAM, featuring a total of 337 million transistors.

Specifications

• 325 Million transistors (235m Parent Die / 90m Daughter Die) (Other specs say 337 million total)
• GPU & Northbridge (Northbridge on Parent Die)
• Two-die design, with two chips in a single package on a single substrate
  • Parent die contains the GPU and memory controller
  • Daughter die consists of the 10MB of eDRAM & additional logic (FSAA, Alpha, ZLogic & Stencil)
  • 2GHz link between the parent and daughter die
• 500MHz processor
• 10 MB of embedded DRAM (By NEC)
• 48-way parallel floating-point dynamically scheduled shader pipelines
  • 4 ALU's per pipe for Vertex or Pixel Shader processing
• Unified shader architecture (Beyond Shader Model 3.0)
• Three SIMD engines with 16 processors per unit (The 48 shader pipeline) 
• 16 Filtered & 16 unfiltered texture samples per clock
• HDR Rendering
• DirectX 9
• Limited support for DirectX 10
• Handles all scaling of video (resolution).

External Links

• ATI Xenos: Xbox 360 Graphics Demystified at Beyond3D