Here's my build:

i5-2500k
gtx 570
8gb g.skill


a lot of the interiors have a ton of slowdown, more than the exteriors, the FPS is kinda bouncin all over the place.

It might. Who knows?

What do you mean by 'ton of slowdown?' I'm running same thing, but a 460, and am swimming along so far. Tweak Guides recommends disabling VSync, which I assumed I would need to do anyway, but haven;t really needed to. Note I'm only 2 hrs in, so maybe I'm not at the interiors you are.

Other processes in task manager? OS?

It's funny I have the same setup as you and noticed the problem. I entered the first interior section where you choose which door to enter and I got this weird feeling like "Man, the framerate seems to have gone way, way down".

Yea. I was in a dungeon fighting like 8 enemies in the interior, and there was no slowdown, than I went into another dungeon, and the FPS dropped dramatically in certain parts, wasn't much of a difference from the dungeons either...

I knocked shadows from Ultra to medium, it made a difference, shouldn't have to though.

One thing about the http://www.tomshardware.com/reviews/skyrim-performance-benchmark,3074.html article- Skyrim seems to be very processor- dependant, more so that most FPS/Action games.

Turning off Vsync actually improved my performance a whole lot and removed the mouse lag, so disabling it will solve your slowdown problems. I'm pretty sure anyway.

That didn't fix it. I don't understand why I switched the 4xaa to 0xaa, and I see absolutely no performance difference, but when I change the shadows from Ultra to medium, most of the problems go away (but it's still a bit choppy in the wilderness.

If you mean micro stuttering, which I'm suffering from too, then no. Disabling v sync just gives you some horrible horrible screen tear and little else.

It's not Micro stuttering, if I look at certain things in dungeons, the FPS drops from 60 to 20.