You do not "flash" it into the BIOS, although I have read that you may need to flash the BIOS. If you are attempting to just do it in the BIOS it will be under the memory config, then the first option you come to will be the correct one, there will be auto and a number of selections, i would probably start off with a 5:4 if there is one, or the smallest ratio. If you need to flash the BIOS you need to download the flash, and then apply it with the flashing tool asus provides with its boards, I have the same BIOS as you, but I dont know whether yours needs flashing. AMI sucks anyway!