The 'numbers in front of the processor names' are comparing the chip's speed with the original 1GHz Athlon (I forgot which build), and are completely unrelated to the actual speed in MHz.
So yes, in general raw processing power a 3200+ 'low end' chip will beat a 2800+ 'high end' chip, 64 bit or not.
Depending on the core the *actual* MHz the chip is running on can vary greatly, but different optimizations and such can still lead to similar ratings.
So yes, in general raw processing power a 3200+ 'low end' chip will beat a 2800+ 'high end' chip, 64 bit or not.
Depending on the core the *actual* MHz the chip is running on can vary greatly, but different optimizations and such can still lead to similar ratings.