for gtx 1080 sli is definitely be an overkill on a 1080 p standard monitor best results will be for 4k monitors , even though to some including myself had 2 gtx 1080s in SLI and wasn't happy with the outcome so I went with 2 gtx 1070s in SLI and have no issues getting 60 FPS even though in games like gta 5 I was getting 80+ FPS and tomb raider 2013 game I was getting over a 100 FPS , waiting to get a 144 hz monitor 4k for it , haven't seen any screen tearing as of yet but i'm sure it will happen sooner or later