[B.0] Horrible lag when shadows not rendered

[rctcool0]

I've noticed that I get some pretty insane lag when I either...
A. Build something that is not "Day" and don't render the shadows, or
B. Render the shadows, add stuff, then race. I also had problems with this in SM.

Also, it seemed to get laggier as I got closer to the non-rendered shadow areas.

Specs:
Asus Sabertooth z77 Mobo
Intel i7 3770k
8 GB Gskill Sniper RAM
Asus nVidia GTX 680 with DirectX 11.0, Driver version 301.42
Mushkin Chronos Deluxe SSD 128GB + 500GB Data Drive (Data drive is where maniaplanet is)
Windows 7 Ultimate x64

ALSO: I'm running this game with Virtu's LucidLogix iGPU+dGPU virtualization and have enabled the Virtu vSync. This is probably why I get amazing FPS.

All settings and sliders set to max, while this may not be efficient, it actually doesn't lag much.