quick question about rampage formula

i am going to get this board this weekend i believe, but it is an open box with a waterblock on southrbidge instead of the heatsink, i heard it only makes minimal difference, like 1degree C. and NB benefits 1-2degree C. can anyone confirm this, or should i find a stock heatsink and put it on there? or does it really matter?
Thanks!

I own the board it is currently resting in my storage closet.
SB is not very hot so any passive cooling will suffice... BUT the nb can get very warm when running high FSB so decent cooling is a must for the NB...