can i sli gtx 780ti with gtx 980

[tofo]

>.> can i ?

 

[Akarin]

Nope. SLI only works with 2 or more cards of the same GPU (i.e. 2x gtx 980).

 

[juggar]

>.> can i ?

No, not even close.

Those two cards have completely different architectures.

Besides, Nvidia is very strict on SLI. AMD's crossfire would give more leeway(Ex. CF 7870 + 7850) in a situation like this but still, you can never crossfire two different architectures.