Skyrim (v1.9) is stuttering like hell on major holds

[WilliamTael]

My Skyrim ver.1.9 is stuttering like hell on major holds (especially outside of Solitude).

Here's a print of my mods installed:

http://fc04.deviantart.net/fs71/f/2014/106/1/3/mods_by_william_tael-d7envfb.png

As you can see, I don't use heavy texture mods, but still my game lags a lot near solitude and major holds.

By the way, my GPU is an ASUS GTX 550 Ti (1GB) and I played Skyrim without that terrible stuttering for months (with the same mods).

I'm guessing the culprit might be SMIM, as for the problem just occurs near major holds or camps.

I already tried to disable ELFX, but didn't made a difference.

Same thing with Animated Clutter mod.

My Skyrimprefs.txt is as default, my NVIDIA drivers are updated and I did roll back the previous drivers, but no luck.

I even formated my system, so don't bother about these things.

I've tried Hialgo's boost, background boost, Skyrim Project Optimization, lowering the graphics settings (everything), reinstalled Skyrim from scratch, set Vsync off or adaptative in NVIDIA control panel and turn mouse acceleration off, but the stutter stays.

UPDATE:

Skyrim sometimes turns my monitor off and on again (like my GPU was giving up), but it only happens with Skyrim (even without mods) and when the screen turns on again, the game runs smoothly.
I have The Witcher 2, Battlefield 4 and Assassin's Creed IV running smoothly and without black screens or stuttering, so not a GPU problem.
My GPU is not overheating by the way.

Edited April 17, 2014 by WilliamTael

[Deleted2823877User]

Do you use LOOT?

Do you have a bashed patch?

[WilliamTael]

No. By the way, what is "LOOT"?

UPDATE:

Skyrim sometimes turns my monitor off and on again (like my GPU was giving up), but it only happens with Skyrim (even without mods) and when the screen turns on again, the game runs smoothly.
I have The Witcher 2, Battlefield 4 and Assassin's Creed IV running smoothly and without black screens or stuttering, so not a GPU problem.
My GPU is not overheating by the way.

Edited April 17, 2014 by WilliamTael