I've checked a number of GTX 980 reviews now:
http://www.pcgamer.com/nvidia-gtx-9...single-gpu-benchmarks-and-impressions/#page-1
http://www.digitalstormonline.com/unlocked/nvidia-geforce-gtx-980-review-benchmarks-at-4k-idnum325/
As expected, the performance nosedives on 4K displays with games set to anything like maximum. The best seems to be maybe 30 FPS and usually more around 20 FPS. This is not surprising, as you're asking the card to drive more than double the number of pixels as 1080p so what suffers is FPS.
The moral of the story seems to be - if you use a single GTX 980 then keep your monitor setting no higher than 1440p.
http://www.pcgamer.com/nvidia-gtx-9...single-gpu-benchmarks-and-impressions/#page-1
http://www.digitalstormonline.com/unlocked/nvidia-geforce-gtx-980-review-benchmarks-at-4k-idnum325/
As expected, the performance nosedives on 4K displays with games set to anything like maximum. The best seems to be maybe 30 FPS and usually more around 20 FPS. This is not surprising, as you're asking the card to drive more than double the number of pixels as 1080p so what suffers is FPS.
The moral of the story seems to be - if you use a single GTX 980 then keep your monitor setting no higher than 1440p.