The Athlon II X2 250 had to use a FSB boost to 260MHz in order to reach a stable 3.90GHz overclock. The voltage was also increased to 1.50v.

Overall we saw decent performance gains provided by the overclock at the cost of power consumption. Although both processors were clocked at the same frequency, the Phenom II X2 550 still provided a considerable performance advantage for the most part.