Skyrim and CC aren't comparable at all in terms of performance. CC is unable to even use a GPU, and is doing pixel by pixel physics every frame. Skyrim is rendering a big ol' world with all kinds of fancy looking graphics, and probably leans on the GPU harder than any other component.

And yet it never uses more than 700MB on my end. Huh.

I remember times when we played Pontifex years ago and it burned our machines almost without any graphics. That game just made some real-time stress simulations. You can't just compare some Skyrim and CC in terms of performance because they're very different.

Also if CC is a 32-bit executable it can't use more that 2 or in rare cases 3 GB of RAM. It will crash once it reaches it's 2GB limit. Trust me, I made it crash this way