The biggest difference between the various lines of processors that AMD has offered us over the past year lies in the cache and the number of processors.  Only the Phenoms have L3 cache and the L2 cache for almost all CPUs is 512KB regardless of the number of cores, only the Athlon II X2 has a model featuring 1024KB of L2 cache.  X-bit Labs wanted to examine the differences in performance, specifically the difference between a dual core with 1024KB of L2 cache and a triple core with 512KB. 

The survey says "16 benchmarks out of 57 preferred fewer cores and larger L2 cache".

"Today we shall try to answer the following question. What's better: a triple-core CPU

with 512KB L2 per core or a dual-core CPU with 1024KB L2 per core? On the one hand,

the former has an additional core. On the other hand, each core of the latter has

twice as much cache available. This isn't as obvious as it may seem."

Here are some more Processor articles from around the web:

  Processors

• CPU

  Performance Comparison Guide Rev. 2.5 @ TechARP

• Intel Core i7 970 Review @ KitGuru
• Intel's Core i7 970 Reviewed, (Slightly) More

  Affordable 6-core @ AnandTech

• Intel Core i5-655K

  Processor BX80616I5655K @ Benchmark Reviews