It continues to baffle me how that I can have two 780 Classifieds in SLI and both only operate in game at 50%. Is this a card issue, driver issue, game issue? The game particular that I am talking about is Dying Light. It would run so much better if they would run at least 90%. Can anyone shed some light on this? Thank you. 

That means, like many other games out there, that SLI is supported but not optimized. For example, when ESO came out that same thing happened - 50% usage on each card for me. Same thing for GW2 (with some spikes into higher usage, but nothing consistent). Sometimes the game engine can't fully support it at the programming level, and sometimes the developer just needs to work a bit more with Nvidia. Hopefully for you and everyone else playing your game it is the latter.