AS8-V/Ram Mobo Questions

I just upgraded from an XP2000 with 1.25GB Ram (512MB PC2100, 512MB PC2700, 256MB something) to the mobo in the title. Now I have a P4 3.0 with 512MB Ram DDR400 (512 hurts...). From what I can tell from the manual, it looks like I can use the old ram in this machine.

How do I do it? Do I have to fiddle about with the uguru thingy in the bios, what do I set things to, and if it is possible, how much of a hit in performance can I expect?

You definite want to retain dual channel, so you need to install the RAM in matched pairs, either 2 or 4 sticks of the same capacity and similar speed. The RAM slots are two colors, so if you use two sticks, they should be installed in slots 1 & 3 or 2 & 4.