? I go from about 15FPS @ KCLT with it checked to a smooth 40-50fps by disabling it
There's something really strange because, on my system (GTX 980, i7 6700, no overclock), I see ZERO performance hit.
This because we never lit up more than 5-6 lights at the same time, and consider the sim supports up to 250 static lights + 250 point lights so, it has been designed to support up to 500 lights!.