Ok so I have 1 x 8GB 1600 and 2 x 4gb 1333, so 16gb ram altogether. the mobo I have from a prebuilt im using GA-h81m only has 2 ram slots. my question is am I better off using the 8gb card being as its 1600, or is there any harm in making use of 1 of my 4gb 1333 cards in my 2nd spare ram card slot on my mobo to make 12gb?