Are you trying to run the game with other mods? I had a hard time trying to find ones that worked... I was using DTR with MB+ and a few other mods which were apparently supposed to be compatible, but it wasn't particularly stable when my mates & I were trying it.

I currently just have DTR loaded with RICE, Muslim Enhancements, some UI mods and a few of the event/flavour pack mods and it seems to be running fine in singleplayer so far

I think it depend on the PC you use. I have only this mod and it's sluggish, while vanilla is much more smooth.

It's normal guys, this mod is fantastic, adds, a lot of stuff, so I suppose the system does a lot of processing, calculations..etc