Yes, first method, through that new dropdown menu.. OK, you need 900, and it's a bit lower than that in first method for 4850's But than you should try Ati tray tools (new beta, see on guru3d forum), it has auto-clocking which alows you to set any clocks speeds, and if you make 2 profiles (2d and 3d) you'll be fine even if RBE or BIOS isn't unlocked and tweaked.

Btw, if you know your max, why don't you just edit BIOS and leave 2d clocks as they are, and 3d clocks to the 900/2150 that you have..?