Can I use these two graphics cards on one PC?

[Noorey]

I have an NVIDIA GeForce 710 and an ATI Radeon HD 5500 Series
My questions:
1) Are these two cards compatible to be used in one computer?
2) Will using these two cards in one computer improve gaming performance? (with SLI cable)

My purpose is to improve gaming performance of my PC

 

[Andrew_T]

Definitely not. You can only SLI two Nvidia cards or Xfire two Radeon cards. There is no interface for different GPUs. Usually there are also limitations within AMD or Nvidia GPUs; some architectures cannot SLI or Xfire with others. Eg. A HD 7850 and a 280X