I believe the DDR2 you're running can do DDR2 1000 @ 5-5-5-15(mine did), that would leave plenty of headroom @ 1:1 ratio. Not much of a chance you'll hit 500FSB with the 2200 or the 7400. If you're worried, get some cheap DDR2-1066. On a side note, to improve overall system response, you may want to think about a hdd upgrade, how old are those 80GB WD?