I am going to buy a new PC with 680 gtx Sli. If I equip it with a i7 3820 not overclocked (I.e. standard 3,6 Ghz), could the 680 gtx Sli be limited by the CPU? Would a i7 3930k be a better choice? Worth spending more money? In a nutshell, if I decide to equip my 680 gtx Sli with a 3930k rather than a 3820 what fps boost range could I expect to gain playing at 1920x1080 all filters ON (AA, AF, AO and so on)?