I already tried it's an old problem unsolved by bioware AND nvidia.
I tried on 780 sli's actually 2x 980Ti kingpin.
Game is working better on 1 card than two but maybe it's time (it's a recommendation) to put more power to this game ^^.
Even with 1 card fps are dropping down when there is more people, more lightning effects etc....
And i'm still impress that the game don't want to use all horse power! Even on little cards like GTX 960 R9 370 etc this game don't want to use 100% of the power.
I don't think that i am bottleneck with a 4930K at 4.8Ghz.
Tried on a 5960X at 4.6Ghz still the same 😉