Im pretty sure I know the answer to this question but Im kind of double checking. Like if you have a motherboard thats DDR3 2000, can you use DDR3 1600 and/or DDR2 1600?
im pretty sure you can go lower with the speed as it will only go as fast as the slowest ram stick but im not to sure about the whole DDR2 and DDR3, i think they operate differently so it might be a bit like stickin a square in a triangle hole.