Correct me if I'm wrong though, but i think you would be hindering that cpu with only sdram in your system. The XP cpu's are designed to be used in ddr systems, and the limited bandwidth of sdram will really hurt you.
Athlon XPs aren't Intel P4s. 🙂
They weren't designed around DDR RAM. They work better with it because of overall system performance increase, but not that the Athlon XP is DDR RAM dependant. An Athlon XP 1600+ will only perform a small percentage better than a Thunderbird 1.4GHz will with DDR RAM, mainly because of the Athlon XP architecture (full SSE, etc).
DDR RAM only improves system performance...my Asus A7V133 would work fine with an Athlon XP.