Anandtech did a cool little preview by overclocking an Opteron to the performance level of a 2.0 GHz Athlon64 (Hammer) chip, running on an nForce3 reference board. They then went on to compare this to a bunch of different processor/chipset platforms. I found it particularly interesting to see that one 2.0Ghz Athlon64 equivalent chip outperformed, or performed equal to a dual 3.0Ghz Xeon system in practically all applications.
