Currently I have 2 GTX 670 4gig Superclocked in SLI. I am a HUGE gamer and I want my PC to perform to the best of its ability. I have an Nvidia Quadro FX 3500 card lying around and I was wondering if I should install it in my 3rd slot and use it as a direct physx card. Is this possible to do since 2 are GTX and 1 is a quadro? If so, should I?
Also, would i have to hook it up with another sli bridge or will it read it if its just sitting in the 3rd slot, since it will just be used for physx?
no point, 2 gtx670's would have more than enough performance to run physx in games. you certainly would not want to hook it up in sli, it has to be the same card for sli. It would hinder performance more than it would benefit you. and waste power also.
Keep in mind, not all games scale properly in SLI mode, some games scale perfectly when adding a second or even a third card but some games aren't optimized enough to make advantage of even 2 cards, so don't bother installing a third. SLI 670s is pretty much as good as it gets when it comes to efficiency in scaling, by installing a third card 99% of games won't even know how to use it