I use EPU-6 software for my i7 920! Without this software i have stutters as hell! If i use it, i put the settings on "rocket" and COD runs smooth and almost without stutters! But don't use the Auto-setting because it don't works right with COD! You must set it manual on the highest level and it works ( makes some noises, but who cares!
)!
It's a freeware from Intel and it's also a good energysafer!