I have a GTX 760 2 Go.
With my current CPU, when i'm in Las Vegas on the crew wild run my fps drop from 60 to 40.
In Assassin's Creed Unity, same, when there is a lot of PNJ around me, my FPS drop under 30.
In Blade And Soul i'm at 60 everywhere, except when i'm with a lof people (PVP Area, 20+ player dongeon party), i can drop to 5 FPS.