time to cook 3 pound rump roast rare
Round or rump roast almost two hours to reach medium rare, 3-pound roast six hours on low or longer. In a crock pot. On the stove top in a Dutch oven around two hours. Extra 15 minutes may be extended for medium or 30 minutes for well done. (source: http://www.ehow.com/way_5260879_long-cook-pound-roast.html).