Xenos (graphics chip)

Specifications

• 500 MHz parent GPU on 90 nm, 65 nm TSMC process or 45nm GlobalFoundries process of total 232 million transistors
• * 48 vector units floating-point vector processors for shader execution, divided in three dynamically scheduled SIMD groups of 16 processors each.
• ** Unified shading architecture
• ** 10 FP ops per vector processor per cycle
• ** Maximum vertex count: 1.21 Billion vertices per second for simple transformed and lit polygons
• ** Maximum polygon count: 406 million polygons per second
• ** XENOS GPU & XENON CPU: 500 million polygons per second
• ** Maximum shader operations: 48 billion shader operations per second
• ** 240 GFLOPS
• ** MEMEXPORT shader function
• * 16 texture filtering units and 16 texture addressing units
• ** 16 filtered samples per clock
• *** Maximum pixel fillrate: 4.00 GPixel/s
• *** Maximum texel fillrate: 8 gigatexels per second
• ** 16 unfiltered texture samples per clock
• * Maximum dot product operations: 24 billion per second
• * Support for a superset of DirectX 9.0c API DirectX Xbox 360, and Shader Model 3.0+
• 500 MHz, 10 MB daughter embedded DRAM framebuffer on 90 nm, 80 nm or 65nm.
• * NEC designed eDRAM die includes additional logic for color, alpha compositing, alpha blending, Z/stencil buffering, and anti-aliasing called "Intelligent Memory", giving developers 4-sample anti-aliasing at very little performance cost.
• * Procedural Synthesis Technology: During read streaming into the CPU, a custom prefetch instruction, extended data cache block touch prefetches data directly to the L1 data cache of the intended core, which skips putting the data in the L2 cache to avoid thrashing the L2 cache. Writes streaming from each core skip the L1 cache, due to its no-write allocation, and goes directly to the L2 cache. The system allows for the GPU to directly read data produced by the CPU without going to main memory. In this specific case of data streaming, called Xbox procedural synthesis, the CPU is effectively a data decompressor, generating geometry on-the-fly for consumption by the GPU 3D core.
• * 105 million transistors
• * 8 render output units
• ** Maximum pixel fillrate: 16 gigasamples per second fillrate using 4X multisample anti aliasing, or 32 gigasamples using Z-only operation; 4 gigapixels per second without MSAA
• ** Maximum Z sample rate: 8 gigasamples per second, 32 gigasamples per second using 4X anti aliasing
• ** Maximum anti-aliasing sample rate: 16 gigasamples per second
• ** Support for bilinear, trilinear, anisotropic filtering, Alpha to Coverage, hardware Tessellation and Predicated Tiling.
• Cooling: Both the GPU and CPU of the console have heatsinks. The GPU's heatsink uses heatpipe technology, to conduct heat from the GPU and eDRAM die to the fins of the heatsink. The heatsinks are actively cooled by a pair of 60 mm exhaust fans. The new XCGPU chipset redesign is featured in both the Xbox 360 S and the Xbox 360 E and integrates the CPU and GPU in one package and is actively cooled by a single heatsink rather than two.