Overclocking-wise, pretty well sumarized :



Strange as it might seem, but a quad-core CPU on Intel Nehalem microarchitecture with Hyper-Threading technology overclocked to 4.0 GHz almost always outperforms six-core CPU from AMD. At the same time I can’t say that Thuban’s frequency potential is higher that of Core i7 CPUs on Lynnfield and Bloomfield cores. Therefore, there is only one possible conclusion here: microarchitecture of contemporary Intel processors makes them faster than AMD processors working at the same clock frequency. And even a 1.5 times increase in the number of computational cores can’t make up for that. That is why we again arrive to the same conclusion that AMD’s only weapon in the battle for consumers is their pricing policy.
1.5 years later old, good i7-920 (which also can do 4.0 GHz) is still an upper-mainstram king.