If you plan to overclock, that's just the wrong memory to even consider... if you will not OC, look for the cheapest available memory. Get DDR2-800 memory if you want good overclocks and if you're buying from the US, it's costs marginally more than DDR2-667... if you want 667mhz memory, my last post has my recommendation... I don't recommend DDR2-533 RAM, but you're free to get it if you want