According to rumors, the future dual-core Phenoms will have the same cache size as the triple or quad-core models. This makes it easy to forecast their performance. Furthermore AMD seems to deliver additional Athlon X2: In our German speaking price comparison the specifications of the Athlon X2 6500 BE
match those of the Phenom X2 GE-6600.
We simulated the Phenoms X2 GE-6600 (2.3 GHz), GE-6500 (2.1 GHz) and GE-6400 (1.9 GHz) by deactivating two cores of a Phenom X4 via MS Config.
The GE-6600 is very fast compared to the Athlon 64 X2 6000+: The dual-core can almost compete with the 3.0 GHz processor. In Grid the GE-6600 is even faster.