i have the original asus crosshair am2 590sli running 2x 1gb memory on win 7,will i notice any difference in gaming if i upgrade to 2x 2gb memory? and should i use 2x 2gb instead of adding another 2x 1gb? would it be better to get memory that has a higher speed for overclocking? any recommendations? will win 7 32bit support 4gb of memory? a good thing would be to run win 7 64bit if im using 2x 2gb and a 1gb video card correct?