Xbox 360/Hardware information

The Xbox 360 continues Microsoft's trend of PC-like architectures for their consoles. While the x86 CPU used in the previous and next two generations is replaced with a PowerPC CPU, many of the same characteristics carry over from other consoles, including unified memory, an NT-based kernel, and forward looking GPU. While there are still some proprietary aspects to the hardware, they are far fewer than competing consoles.

CPU

• 3c6t PPC Xenon @ 3.2GHz
  • Derived from Cell PPE/PowerPC 970
  • SPEs replaced with SIMD extensions and larger vector registers, known as VMX128

Things to note: Lacks out of order execution. Very long pipeline, manual branch predictor, making it terrible at code that requires CPU "agility". Clock speed and core count gives deceptively high on paper performance.

GPU

• ATI Xenos @ 500MHz
  • World's first unified shading GPU
  • TeraScale uarch
  • 3 "SIMD cores" (predecessor to CUs)
  • 8 ROPS
  • 16 TMUs
  • 240 shaders
  • Direct3D Feature Level 9_0c, with some things from higher feature levels (mainly FL 10)
  • MEMEXPORT allows for GPGPU compute
  • Connected to 10MB of eDRAM framebuffer
    • eDRAM has extremely high bandwidth and PIM for free MSAA at 720p and low-cost at 1080p

Things to note: If using data from MEMEXPORT on CPU, you must enable both d3d12_readback_memexport and d3d12_readback_resolve in Xenia's options or use HW!

Useful Links

General

https://en.wikipedia.org/wiki/Xbox_360_technical_specifications

https://www.copetti.org/writings/consoles/xbox-360/

Xenon

https://github.com/xenia-project/xenia/blob/master/docs/ppc/core_instructions.pdf

https://github.com/xenia-project/xenia/blob/master/docs/ppc/altivec_instructions.pdf

https://github.com/xenia-project/xenia/blob/master/docs/ppc/vmx128.txt

Xenos

https://www.techpowerup.com/gpu-specs/xbox-360-gpu-90nm.c1919

https://learn.microsoft.com/en-us/windows/win32/direct3d9/dx9-graphics-reference

https://learn.microsoft.com/en-us/windows/win32/direct3d9/dx9-graphics-programming-guide

https://learn.microsoft.com/en-us/windows/win32/direct3d10/d3d10-graphics-reference

https://learn.microsoft.com/en-us/windows/win32/direct3d10/d3d10-graphics-programming-guide

https://xenia.jp/updates/2022/01/29/presenting-the-presentation-update-amd-fidelityfx-fsr-fxaa-cas-vrr.html

https://en.wikipedia.org/wiki/Unified_shader_model