I'm not sure if anyone can tell you for sure the exact impact it will have unless they are running a very similar build.. Triple screen isn't the issue it's the resolution you run that makes the difference.. Something like 5760 x 1080 is a huge resolution to compute for... And as Ryzza says it depends on the AI and other things on screen that need to be worked out is what needs all the power. And large resolutions like that often need more video memory....like the 4GB cards - and two 2GB cards doesn't necessarily equal the same as a 4GB card (from the little I have read anyway).
I'd do plenty of research before going further IMHO.
I have an old Q8400 quad 2.6Ghz CPU running with a GTX750Ti 2B OC card and in AC in practice (on pretty much Ultra settings except for AA I can hit the 60-70 fps mark....but thats on one screen at 1920x1080. But during a race on a modded track in a modded car with 5 cars on track I have seen the fps drop to high 20's-low 30's in certain spots around that specific track, so it is all a big variable in reality - there isn't a constant (accurate) measure you can really go by as far as I can tell.
Last edited: Sep 25, 2014