Bt i ve heard....
For surround setups...more memory is required n which is nt fullfilled by da gtx680....
Da 680 has 2gigs f memory whereas 970 has 4gigs...
Hw mch f a difference would that make
The 970 isn't powerful enough to properly run 1080p Surround or 4k by itself. The 970 is significantly more powerful than a 680. Some games like Crysis 3 aren't playable at Surround resolution, and some other games like BF4 are barely playable with lower settings. VRAM isn't an issue here, it's simply the amount of power the GPU has to push such a resolution.
This. 2 960s would be the cheapest option, but that'll only give you enough performance to run medium-high settings with no AA. A friend of mine has 3 780ti in for his Surround and he still has issues with some games.