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Vertex Engine

Performance Leap: NVIDIA GeForce 6800 Ultra
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The vertex shader units also conform to Microsoft's DirectX 9.0c specification, meaning Vertex Shader 3.0.

Vertex Shader Summary
Shader Model 2.0 2.0a 3.0
#of instruction slots 256 256 >= 512
Max # of instructions executed 65535 65535 65535
Instruction Predication - Yes Yes
Temp Registers 12 13 32
#constant registers >= 256 >= 256 >= 256
Static Flow Control Yes Yes Yes
Dynamic Flow Control - Yes Yes
Dynamic Flow Control depth - 24 24
Vertex Texture Fetch - - Yes
#of texture samplers - - 4
Geometry Instancing Support - - Yes

The vertex engine has seen a great range of improvements and extensions compared to the NV35 / 38. NV40 possesses 6 vertex units which follow a MIMD (multiple input, multiple data) design. NVIDIA also sets a new record with a triangle transform rate of 600 million polys/second (Radeon 9800XT = 412, FX 5950 = 356).


Vertex shader programs can theoretically be of infinite length in VS 3.0. Thanks to the extension of the dynamic flow control (more looping / branching options and new subroutine functions), shader code can now be written much more efficiently and offers new options for effects.

Again, here's summary of features:

  • Full Support for Shader Model 3.0
  • 216 (65,535) length vertex programs
  • Vertex processing w/texture - displacement mapping
  • Dynamic flow control - Branching, Call & Return, Subroutines
  • Geometry Instancing (vertex stream divider)
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