Nehrim Performance Problems

I've been playing Nehrim lately due to the recommendation from The Tek(thank you BTW) but my performance is horrid. I'm running everything as high as it goes and in the overworld my frames drop to around 30 - 40, sometimes even dipping below thirty. I can run Oblivion at max at 60 without problems, heck even Skyrim, but Nehrim is a different story. Does anyone else have these performance issues? (Quick spec rundown -> i7 3930k 4GHz, Gtx 480 @ 750MHz/1900MHz, 4x4 1866MHz Ram. 1920 x 1080 4xAA)

Simple answer:

The Gamebryo engine is terrible.

Slightly more detailed answer:

The Gamebryo engine runs crap even on good PCs.

I understand that, but both Gamebryo games I own(TESIV/Fo3) both run at 60 no problem with max settings. In fact, I normally have graphical mods such as texture packs installed and still play without a hitch. This problem is only present in Nehrim.

What he said...

Gamebryo runs fine for me, but it sure as hell crashes a lot...