for a 4gb(DDR 2 800mhz) ram setup,which combination is the best??? 1.)4x1gb sticks,(will it act like two seperate dual channels??) 2.)2x2gb sticks,or 3.)2x1gb+1x2gb sticks(two 1gb sticks and one 2gb sticks,would there be any problem with this??also,would there be any problem if the 1gb and 2gb sticks are from different manufacturers??) thanks in advance for the answers.