RSX Reality Synthesizer

Length of chip at bottom: 4.28 cm

The RSX 'Reality Synthesizer' is a proprietary graphics processing unit (GPU) co-developed by Nvidia and Sony for the PlayStation 3 game console.

Unless otherwise noted, the following specifications are based on a press release by Sony at the E3 2005 conference, slides from the same conference, and slides from a Sony presentation at the 2006 Game Developer's Conference.

Specifications

• 550 MHz on 90 nm process (shrunk to 65 nm in 2008 and to 40 nm in 2010)
• Based on G71 Chip in turn based on the 7800 but with cut down features like lower memory bandwidth and only as many ROPs as the lower end 7600.
  • 300+ million transistors
  • Multi-way programmable parallel floating-point shader pipelines
    • Independent pixel/vertex shader architecture
    • 24 parallel pixel-shader ALU pipes clocked @ 550 MHz
      • 5 ALU operations per pipeline, per cycle (2 vector₄, 2 scalar/dual/co-issue and fog ALU, 1 Texture ALU)
      • 10 floating-point operations per pipeline, per cycle
    • 8 parallel vertex pipelines @550 MHz
      • 2 ALU operations per pipeline, per cycle (1 vector₄ and 1 scalar, dual issue)
      • 10 floating-point operations per pipeline, per cycle
    • Floating Point Operations: 176 GFLOPS (24 * 10 FLOPS * 550 + 8 * 10 FLOPS * 550)
      • 74.8 billion shader operations per second (24 Pixel Shader Pipelines*5 ALUs*550 MHz) + (8 Vertex Shader Pipelines*2 ALUs*550 MHz)
  • 24 texture filtering units (TF) and 8 vertex texture addressing units (TA)
    • 24 filtered samples per clock
      • Maximum texel fillrate: 13.2 GigaTexels per second (24 textures * 550 MHz)
    • 32 unfiltered texture samples per clock, ( 8 TA x 4 texture samples )
  • 8 Render Output units / pixel rendering pipelines
    • Peak pixel fillrate (theoretical): 4.4 Gigapixel per second
    • Maximum Z sample rate: 8.8 GigaSamples per second (2 Z-samples * 8 ROPs * 550 MHz)
  • Maximum Dot product operations: 56 billion per second (combined with Cell CPU)
  • 128-bit pixel precision offers rendering of scenes with High dynamic range rendering (HDR)
  • 256 MB GDDR3 RAM at 700 MHz
    • 128-bit memory bus width
    • 22.4 GB/s read and write bandwidth
  • Cell FlexIO bus interface
    • 20 GB/s read to the Cell and XDR memory
    • 15 GB/s write to the Cell and XDR memory
  • Support for PSGL (OpenGL ES 1.1 + Nvidia Cg)
  • Support for S3TC texture compression

Press Releases

Sony staff were quoted in PlayStation Magazine saying that the "RSX shares a lot of inner workings with NVIDIA 7800 which is based on G70 architecture." Since the G70 is capable of carrying out 136 shader operations per clock cycle, the RSX was expected to feature the same number of parallel pixel and vertex shader pipelines as the G70, which contains 24 pixel and 8 vertex pipelines.

NVIDIA CEO Jen-Hsun Huang stated during Sony's pre-show press conference at E3 2005 that the RSX is twice as powerful as the GeForce 6800 Ultra.

See also

• Xenos (graphics chip)