If you pay a little bit more, you can have these: Corsair Twinx 1024MB XMS3200 - CL2/HSP (2x 512MB - 400Mhz - Matched Pair - CL2 - Heatspreader) They are tested and guaranteed to work in a dual channel configuration. Working fine in my new PC I just put together <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />