Thanks for your replies!
Honnestly I am not really interested in a monitor upgrade. I understand the 1070 is too much for 1080p @ 60 Hz. I had previously a 1060 and upgraded because I found a good deal on the 1070 and I mined a little bit (no shame).
This benchmark shows some pretty good improvement in multicore applications.
Honnestly, I think the era where single thread>multi core is over. Any game I played the last 2 years used equally all of the cores. Games like FC5, AC:O, Crysis 3, The Witcher 3 and KCD (this badly optimized mofo is at 90% all the time) made use of a lot of CPU ressources