I recently built a new machine and was unable at the time to find Cas4 memory that was in stock. So i went ahead and bought the Cas5 (5,5,5,12 at 1.9v) Memory. Now my question is how much of a performance gain could i get or see with trying to exchange for Cas4 i have read that the Cas4 has a lot better over clock and performance anyone have any experience or knowledge of this? Thanks a head of time.