Interestingly enough, I can run Skyrim at a solid 60 FPS with 200+ mods, full res, and high-ultra quality yet New Vegas I can only get 30-40 FPS. Investigating it I noticed my CPU is the bottleneck, with one of my 8 cores running at near 100% utilization while my GPU doesn't even crack 50%. I've tried all the multi-threading ini tricks, CPU parking app, etc.. and while they smooth things out a bit perhaps, they don't do much for FPS, nor seem to spread the load to other cores. I've accepted this is best I am going to do with multi-threading, what I want to research next are what ini/graphics settings impact CPU? For example shadows apparently use CPU and know from Skyrim that is the one thing I had to tweak to get my 60 FPS in some of the busier areas. In Skyrim, smoke also seems to impact CPU. In both games I think scripts are very CPU impacting so that might be something to look at, perhaps avoiding script intensive mods, turning off some perks, etc...

What settings can be changed that should have a noticeable impact on CPU utilization?

For ref: I have an i7-2600 3.4GHz (no overclock) and a GeForce GTX 760 w 4Gb. Using stutter remover, NVSE, and 4GBFNV.