DiffNoise.fx – DirectX 8, 3D noise texture, 1 light source:

When the object is transformed, its texture appears “noisy” - quite a weird effect.

Dispersion.fx – light dispersion shader, DirectX 8, texture, assembler, fixed functions:

Ghostly2.fx – DirectX 8, transparency, texture, assembler:

So, the test results suggest that DirectX 9 shaders are generally much harder on the graphics cards compared to their DirectX 8 analogs – that's the price you pay for higher settings flexibility, new capabilities and easy programmability.