If your RAM is running at 1600 already, you will have to lower the multiplier on it.
But if it is running at 1333 (default for most AMD mobos), you should be able to slowly raise the FSB and test stability until you reach 1600 on your RAM. Then lower the multiplier on RAM and continue.
Each chip/mobo/RAM is different, and settings for one person may or may not work for another. Luck of the draw if you get a good one or not!