This is not possible because the two memory boards are designed differently. A DDR3 memory won't fit at all in the slot for DDR2 memory. The same holds true if you want to add DDR2 memory to a DDR3 slot. However, they did build a few motherboards that you could either use DDR3 or DDR2 on the board. These boards gave you the choose what memory you want to use. They had 2 slots for DDR2 and 2 slots for DDR3. If your motherboard has this option then you can use DDR3 on this board.