http://www.gamersnexus.net/guides/1970-gtx-980-ti-sli-benchmark-vs-sli-980-titan-x?showall=1

So it must be amazing to know 980s in SLI get better performance than all 12g routinely in 4k right?

DeludedRaven
http://www.gamersnexus.ne...-980-titan-x?showall=1

So it must be amazing to know 980s in SLI get better performance than all 12g routinely in 4k right?

I'm not sure I see your point? Isn't that more than a little obvious without even looking at the benchmarks? I doubt anyone here is under the impression that a single 980Ti/Titan X would beat two 980s in raw FPS and if they are then they know absolutely nothing about hardware.
 
The Titan X and 980Ti are far superior to the 980, of course not the >100% performance increase that you were apparently expecting but rather a more than reasonable ~30% FPS increase. VRAM usage at 4K has been shown to exceed 4GB in several games. You will therefore experience stuttering, texture loading delays and generally inconsistent performance in those games with SLI 980s regardless of the FPS. I know I'd personally prefer to spend an additional $150 per card in order to prevent those issues for at least another 8-12 months rather than experiencing them from the day the cards are delivered. If you're intending to play at 4K and are going to purchase two GPUs and a 4K monitor then I think you'd be pretty silly to buy two 980s.