i have a ECS K7S5A motherboard, currently with a 1.1ghz duron and 512mb pc133 ram. i'm going to be replacing the duron with an athlon XP in the near future. when I do that, would the pc133 drag the cpu down considerably? if/when i upgrade to DDR ram, what speed should I get? pc2100, 2400, 2700, etc... thanks