All cards produce adequate performance in the Far Cry test, which is set to maximum image quality. The X1950 Pro is around 10% faster than the X1900 GT, with the gain being accounted for, in the main, by the faster memory used on the Pro.
Again, it's all much of a muchness in Quake 4. All cards produce more than acceptable framerates at both image-quality settings. A lack of performance deviation from GT to Pro is, perhaps, down to the CPU-intensive nature of the Quake 4 engine.
Splinter Cell: Chaos Theory
The Radeons assume control of Splinter Cell: Chaos Theory, easing their way ahead of the NVIDIA 7900 GS 256MiB card.
The Sapphire X1950 Pro results should come as no surprise. The RV570 GPU packs in a greater number of features than the R580-derived X1900 GT, but, really, with a similar underlying architecture, performance is dictated by core/memory clocks.