Normally to figure out what you can clock system 1 at is...
I drop the ram as low as possible and set the chip to as high of muilti that I can use. Then max the cpu. for your setup I would guess there is a dram/cpu ratio setting somewhere this need to be low as possible. 2:3, 5:4, but not 1:1 or 50% not 100% of cpu. Then once you have found your max mhz for the cpu you have a idea of where you need your ram and muilt to be set for best performance.
Also you may or may not be able to hit as high of an oc with ram and board running low. Once you put everything in sync instead of async you might have to run a lower cpu clock speed then what you could get with dram lowered...
