Go to AMD home page and see the page where is writed about motherboards which they recomend for 1GHz - 1.3GHz duron, I know that the A7V133-C(no raid) and A7V333(no raid) is well working with Atlon 1600XP+. In AMD page for 1.2GHz Duron is recomended A7V266 but this is probably because thay aren't updated the page!