From my viewpoint Physic processing and Cuda programming is more important then what 10.1 brings to the table. Unfortunately looks like PhysX and Cuda is only going to be Nvidia Centric, like 10.1 is to ATI. I also believe if hardware PhysX was available in a game which also had a DX10.1 options, that the PhysX version would out perform what DX 10.1 version could give, generally that is. Doesn't 10.1 expose hardware tesselation, which could be used very beneficially in a game and make a extra feature for those with 10.1 cards without any or little performance lost. Plus games on the XBox360 that uses the tesselation hardware could also use that on ATI 10.1 cards.
So there is give and take, presently PhysX has real use, while limited today in hardware. DX10.1 maybe tomorrow.
All said and done, I am leaning towards ATI for my next purchase for totally different reasons
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