The plot thickens....
"A story which just recently hit the web documents that NVIDIA's latest GPU, released earlier this week, the Geforce FX, may not support Microsoft's DirectX 9 feature set in full hardware.
The technique, or feature, in question, is displacement mapping. Microsoft iterate that displacement mapping is based on the N-Patch approach, introduced by ATI over a year ago. This obviously segregates it from the version NVIDIA implemented with the GeForce 3 GPU, i.e. RT-patches. This parametric surfaces solution was later disabled for the Geforce 3 cards as initially posed an operation which resulted in compatibility issues."
Read here for more.
Somehow, methinks that anything by NVIDIA will do just fine...