I have the same freeze problem.
I only have half the s.t.e.p. mods and a few of my own, but with a clean fresh save I get freezes and I have to use CTRL+ALT+DEL
And I do use my SSD for Skyrim, so thats out of the question too.
I know better use clean saves etc, but if I load an old save it doesnt freeze somehow, I have no clue why (maybe old scripts that dont freeze the game?)
My rig is:
Intel Core i5 2500K @ 4,3GHz (watercooled)
16GB ram
Windows 8 x64
Club 3D HD6970 2GB (watercooled) not overclocked
So its not a temp problem in my case and I use to run Skyrim without a problem.
I am trying to figure it out for a few days now and its kinda driving me nuts lol, cant find why it happens.
Like others say, Skyrim is around 2,5gb ram usage when it happens.
Ow and I dont even get out of helgen keep yet lol, so it happens inside, not even in the world.
And yes its at random moments, never at the same place.
Greetz Tony