It doesn't depend on the ram or the CPU, it depends on the motherboard. (seeing as your memory controller is on the CPU, it does depend on the CPU in your case.) Its a setting you change in the bios. Seeing as we don't know what motherboard you have, I/we have no idea what you should change.
Depending on how your Bios is setup, its either done by putting the ram speed to either 1:1, or ???