Is it possible to do SLI with NVidia GeForce GTX 570 and GeForce GTX 260?

Guys I am here to ask some questions with you all don’t know if you all can answer me about the same, so what I want to say is that I am having a sli with the current card i.e. GTX260's. next month I am planning to get a GTX570 as well. So is it possible to sli both the cards and if yes then how. Better would be if you all can explain me in some steps that would be much better for me, so do reply accordingly on the same I am waiting for the response from your side.

No dude just leave behind that idea you would not be able to do that at all, so that’s what I want to say here. I hope that was ok for you. Good in imagination but does not look real at all. I hope that was sufficient for you.

Dude I got a GTX570 and GTX260's. dude you will not believe that it is working well with both of them using the Physx. Dude it works fine for me getting around 45-60 FPS for a very hardcore game like batman arkham city, I think that’s a great achievement that’s what I can say here.

According to what I know is that you can only SLI the same GPUs and the graphic cards having different gpu’s cannot be sli. That’s what I know now there can be a possibility that I might be wrong about the same. anyways you all can go ahead with the same. so that is what I want to say here.

I hope that was enough for you all, that’s it from my side.