Why AMD dual core? The Phenom IIs are great, but the 7750 is based on the horrible original phenom. Intel is much more overclockable for the same price. 4670 will be fine for the sims 3. Specialk, you don't understand efficiency. A 400w psu puts on 400w, regardless of its efficiency. A higher efficiency PSU will draw less power from the wall to get the same output. Get a PSU from a reputable brand like Corsair, PC Power and Cooling, or Antec.