dreamshapers :
Thanks for the prompt answer. Regret the inconvenience caused by putting out a wrong question.
Rephrased: Can they work on crossfire.....
Nope unless some kind of magic happens.
Nvidia and ATI won't work together.
I dont think a GTX card would even work in sli with an Nvidia Quadro card.
As far as I am aware to SLI or CrossFire you have to have the same card (ex. 650/650, 7970/7970, and firepro/firepro), except now with AMD with their APU and GPU crossfire shenanigans.