Calling all owners of Asus Rampage II extreme mobo - help!

Hi. Super noob here.

I need some help because I don't know what I'm doing. I have overclocked my i7 920 to 3.6 (19X200 bclk) but have managed to do this only by reducing dram frequency to 1200. In fact I have 3X2 1600 ddr3 ram, but with the cpu overclocked as stated I can't use the memory at this frequency (I'd be doubly grateful if someone could explain why not).

Anyway, someone has told me to turn the ram voltage up to 1.65 - by which i suppose he means the dram voltage in bios and to set memory multiplier from x6 to x8 and do the same with the uncore multiplier. Fine. My question is: where do i find this multiplier in the asus bios?! I don't think there is one!

Please, can someone point out the blindingly obvious to me and help me get my ram up to speed whilst maintaining this overclock.

when the ram gets too much power and unstable it shuts down, you gotta turn it down when u clock the cpu cuz you're overclocking it all, not jus the processor, so its best to turn it way down, get your cpu where u want it, the go back up as much as you can with the ram.

On older asus boards you have several dram frequencies to pick from - and those are your Ram speeds on different multipliers. It may be similar on your rampage - those speeds should change when you change the bclk, check it.