I see Xeon and I7s in the top ten benchmarks for cycles in the Mike pan Benchmark for cycles the best single cpu was the i7 3930K it got a time of 2 minutes And it is a 60 Gflops cpu I have a amd a8 sires cpu (I don't know the exact model and it does not matter) and it is overclock to 5ghz witch is also a 60 flop cpu And it takes 5 minutes to render the same scene The point is why are intel cpus with the same computing power as an equivalent Amd cpu rendering the sceen so much faster
As far as which is better for Blender, AMD or Intel, I don't really know. Beside, if the benchmark is using cycles, they might have been using GPU rendering.
As for why Intel CPUs tend to outperform AMD, the quick and dirty answer to this is that Intel has more money to spend on R&D. There was a point in time where AMD had better CPU's than Intel (Atholon 64 vs Pentium 4), but this caused Intel to get their act together. AMD is making some nice improvements to their processors, but the resources they can invest in coming up with a better CPU doesn't even compare to what Intel can invest. Because of this, Intel is more likely to come up with a better CPU.