bit-tech have a look at one of AMD's first 65 nanometre Brisbane processors.

The one interesting decision that AMD has made is the increase L2 cache latency on Brisbane - the performance deficit between Brisbane and Windsor wasn't massive, but it was distinguishable and fairly consistent over the course of the application benchmarks we've shown here. This leaves me a little perplexed, but the explanation that there's the potential for 65-nanometre Athlon 64 X2's with larger caches if there is a need to move to much larger cache sizes seems a fair one.

Athlon 64 5000+ 65nm review