The_Freeman :
burdenbound :
Probably not all that good, but I would point out that unless you have no bezels on your monitors that game would look horrendous. IMO you either go one monitor or three.
How would it do on 3 then?
Not good at all, if your planning for multiscreen, I would recommend an R9 290 or gtx 780 at a bare minimum. You will need a graphic(s) card with a high amount of VRAM (4GB+). If you really wanted decent performance with triple 1080p look into SLI/crossfire. You could probably get away with using a 970 or R9 290x though.
There isn't really a way around dropping some serious money though, unless your willing to drop the quality settings a lot.