I dont have any knowledge on ram. cas ?? lower the better.....i think?? buffered / registered ??? clueless.. I'm currently using 1gig stick of generic pos ram. my motherboard is the Asus P5W-DH Deluxe. DDR2 800 is what newegg says i use for ram. i would like to get 4gigs but since i'm on a budget 2 gigs around 150dollars total. want to upgrade to vista hince need more ram. thank in advance.