Agree with simon12. I've have that processor you're asking about, the 955 BE and run it with 1600 MHz ram. Using it with the m4a785td-v evo and it works fine, the motherboard box actually says OC 1800+ so it encourages you to OC. As simon said, 1600 is an OC'ed rate so no one will support it. Legalities and stuff.