who tells u that ppl are using ati card and nvidia card for physx.do so googling before posting.
Even if there aren't problems with it. I wouldn't reccomend it. How many games out there acutally use Physx? And I think only 2-3 of them are worth playing.
Its not worth the heat, power consumption, and its not worth having to deal with multiple drivers and what not.
Plus judging by his post and the fact he uses multiple monitors he wants to use the cards to boost his performance, as in a SLI or CF setup.