GPU

Xenos

File:X02056.jpg The original Xenos, Y1
Introduced	Late 2005
Designed By	ATi Microsoft NEC (eDRAM)
Codename	ATi C1
Type	GPU
Used In	Original Xbox 360
Clock Speed	500MHz
Memory	10MB eDRAM
Successor	XCGPU

Xenos, codenamed C1, is the graphics processor, northbridge, and memory controller used in the Xbox 360. It also has an NEC designed eDRAM which contains additional logic.

The processor was developed by Microsoft and ATi, and the first version was codenamed Y1, which stands for Year 1.

Specifications

GPU

• 500Mhz clock speed
• 48 floating-point vector processors divided into 3 dynamically scheduled SIMD groups (16 each)
• Unified shader architecture
• 16 texture addressing units
• 16 texture filtering units
• 8 pixel rendering pipelines
• Direct access to CPU L2 cache

eDRAM

• 10MB 256GB/s eDRAM
• Contains logic for:
  • 4-sample anti-aliasing
  • Alpha compositing
  • Color
  • Z/stencil buffering