i just gone from 955 to intel 3570k in a lot of games it is double the speed
the 955 didnt struggle with anything.that is at stock as well
i sold my stuff for 120 and the i5 set up was 300 . so 180 isnt too shabby and it is a big increase. best youll get is 10-15 percent on next chip and you wait 6 months.
double the speed is really putting it out there ! especially with no evidence or explanation where you see the gains.