ya 4GB does limit your FSB options, it also depends on the memory of course. I can hit a lil over 450 fsb with 4 dimms in use, and over 500 with just 2 pretty easily, but i like my 4GB so the lower FSB, so i live with it. Gonna prolly will take 2 sticks out soon though and transfer them over to my 650i board in a week or so, once i get that machine back on its feet. Or just buy a kit of crucials, they are 48 bucks after rebate on egg for 2gb