I'm not sure how credible Xbit is but they claim to have done some quick tests on AMD's newest processors.
http://xbitlabs.com/articles/c...om-athlon-ii-x2_2.html
http://xbitlabs.com/articles/c...om-athlon-ii-x2_2.html
This is a very good result, showing that dual-core AMD processors on 45nm cores will overclock way better than their triple- and quad-core fellows. The results of our Phenom II X2 550 overclocking experiments confirm this assumption as well. This processor remained stable at 3.98GHz frequency with the core voltage increased by 0.15V.