You should look at those new benchmarks done by Digital Foundry testing the new 980ti at 4K, you can get really decent fps at 4K notably with the Overclocked 980ti:
http://www.eurogamer.net/articles/digitalfoundry-2015-nvidia-geforce-gtx-980-ti-review
They really think this card, the 980ti is great for gaming at 4k or new 3.4k panel but still advise to wait before the 390x AMD release to better compare both cards.
And also directx 12 should improve those numbers significantly in the near future (~30% improvement allegedly).







