Your board runs at pc5300 speed (which is the same as ddr2 667). But if you find ddr2 800 (pc6400) for less, then you can use that memory. The board will default to the lower speed. I use micron and samsung memory on my asrock board. Use pairs only that are rated for the same speed; I have one pair of micron and one pair of samsung pc5300 in the 4 slots; all are color coded, with one branded pair in the yellow slots, and the other in the orange slots.