I would say that due to it's top notch single threaded performance accompanied by very good, but not superb, multi threading performance it'll most likely work very well with Two 980 Tis. Just use 4K to minimize the bottlenecks that are possible, but only in the most CPU intensive of games.
Plus, i think the only CPUs to outclass the 6700K's multi threaded performance are the Haswell-E Series. (i7-5820K, i7-5930K, i7-5960X)
Once again, the 6700K is better for single threading than any of those 3.