Athlon OC has an article on how to optimize yer DDR mem...
Full article: http://www.athlonoc.com/reviews.php?op=showcontent&id=11
This primer is the first of a series of articles meant to give you a better technical understanding of how your memory interacts with your motherboard. Unlike some of the other memory guides out there, we intend to provide the information in a manner which will allow you to gain the most from your particular motherboard / memory combination. We try to explain the facts with out going into the how and why of it.
We leave that to the engineering types who write for Aces and Lost Circuits.
Full article: http://www.athlonoc.com/reviews.php?op=showcontent&id=11