NF7-S FSB/DDR ratio [auto or 1:1]

Another newbie question, I want to run my memory in sync (ratio of 1:1). Does it matter if I choose:

1:1, 3:3, 5:5, 6:6 or auto?

Thres an 1:1? I couldnt find it

Sorry That list is from memory. What I'm still at work. But there was auto and X/X where the ratio was 1:1. I was just wondering if there's a difference between auto and manually setting a ratio that equals 1:1

AFAIK, if you set it to auto, it'll run the FSB at the lowest FSB between the CPU and memory. Since you have a 2500, setting it to auto will make it run only at 166mhz. Since you get the best performance running it in sync, you should remove it from auto and place it at 6:6 or any other 1:1 ratio.