I have no problem with the fps i get in the game... I allways get about 45-60 Fps (it depends of the areas)

But the only moments when the fps drop are in places whit a lot of fog and light, for example, when I enter in the "Frostflow Lighthouse" (located between Dawnstar and Winterhold) the fps drop about 15 just in the entrance, baceuse there is a lot of light and weird fog inside.

Is there a way to solve this? it is not a major problem because is only in that exactly place but is anoying

I think is no problem of mi pc:

- 8 gs of Ram
- 550 Gtx Ti
- Intel i3 3.2 Ghz
- Win 7 64 bits
(I run the game with all in hight and i get allways between 45-60 Fps)

And escuse me my bad english is not my native language

Take a look !

http://www.gamesas.com/topic/1323347-how-to-fix-indoorcavedungeon-fps-drop/

Thank you a lot, that will help me a lot

That tweak will help alot with large fps drops, the drops in frostflow lighthouse should be mostly gone but there is a problem still with the falling debris in helgen's stairwell. The debris particles if your looking directly at it will drop my own fps by 20 to 30. Not sure how to fix that yet...

This will remove all fog and mist. It will provide a huge FPS boost in those areas:

http://skyrim.nexusmods.com/downloads/file.php?id=736

I had to use this when the game was new, before Skyboost and a lot of other tweaks. I like the mist and fog, personally. Some don't even like it.

@Mr Reiper

Hoping this might be a good choice for you...
http://skyrim.nexusmods.com/downloads/file.php?id=6387 by VirusType2 aka Vergis

Thanks for the suggestions, the dust that falls from the celling can be reduced via:

[Particles]
iMaxDesired=500

I was using 750 and for some reason that would make such an impact on my performance. I have good specs on my pc I just play using huge amounts of transparent aa, its a must for me as I can't stand the tree leaves, foliage and dynamic snow textures shimmering... *eck*

So if anyone one else like me uses ridiculous amounts of trssaa and has lag then these options are the culprits in my own testing:

SkyrimPrefs.ini
[Particles]
iMaxDesired=500 (or lower, 250 works well too. Only effects certain particles!)

Add to Skyrim.ini
[LightingShader]
fSpecularLODFadeEnd=0.0
fSpecularLODFadeStart=0.0 (In my testing if these are not 0.0 then you get a performance hit)

These were the last things getting in the way of my skyrim experience. Now I can play the game. woop, woop...

@Mr Reiper
Oh! I've mistaken the meaning of "the falling debris." But the problem has already been solved in that smart way... Great !