Shader Model 2

Shader Model 2 added additional capabilities to shader model 1.

Feature Capability
Instruction Set
Register Set
Pixel Shader Max
  • ps_2_0 - 32 texture + 64 arithmetic
  • ps_2_x - 96 minimum, and up to the number of slots in D3DCAPS9.D3DPSHADERCAPS2_0.NumInstructionSlots. See D3DPSHADERCAPS2_0
Vertex Shader Max 256 instructions
Shader Profiles ps_2_0, ps_2_x, vs_2_0, vs_2_x

 

For more details on shader model 2, see:

Shader Models vs Shader Profiles