I have a Gigabyte Motherboard P55A-UD6, had 2x2GB 1600MHZ Ram Memory... the main diference (and only) between rams is the Voltage (the new is 1.6 (4x2) and the old is 1.8(2x2)) I have updated the Bios to F7. Id like to know what I can do in other to make all Ram chips to work. Had 4GB, wanted to upgrade to 12GB. Currently have 8GB. Is there a option in Bios Maybe? Thanks for the help everyone.