I have that same CPU Asrock z77 extreme 4 motherboard Evga gtx 660ti superclocked 8 gb Kingston hyper x ram And a just a mechanical hdd from my old rig I run Skyrim on ultra settings easily with 60fps. I also have about 30+ mods on it. Fxaa ppi, HD textures, W.A. T. E. R, lush trees, etc. I have a bunch of visually enhancing and retexture mods on as well and armor and weapon mods. I still get 55-60fps almost always. The only time I see drops is when transitioning to a scripted event and when quick saving. During those times it drops to the mid 40's for a split second. If I were you I would get the ti version. You should be fine bro.