I already own a 1080TI. I get solid performance at 4K, but could be better as sometimes in games the system drops down to 30-45fps. So I'm looking to upgrade. I can't decide if I should go SLI route (thus getting better performance in some games, but possible multi-gpu issues), or go the single card route. I've had 4-way multi-card at one point and I remember the problems I'd get occasionally; makes me want to steer clear. Anyone have 1080TI SLI want to chime in on their experience?