Yep, the ram speed will always depend on the reference clock, as well as the CPU multi. There is a nice chart HERE
, that will show you what I mean.
There is another option... you can just set your CPU multi to 15 and you'll be at 3GHz right away, although you might need a little more vcore at some point. My friends BE runs at 3.1GHz at stock voltage... so you should be good to go.
I just got my 4600 brisbane up to 3GHz (left my window open at night... and in the morning had low enough temps to get a little more out of it.. i was idleing at 13c, instead of 22...), and with my new 9800GT (non OC'd) I score 10087 in 3Dmark06, so I think that once you get your BE up to 3.0-3.2GHz, that you'll definitely beat that.