Not sure if I understand that question.
The building materials for a stepping series are fundamentally similar. The manufacturers, like Intel and AMD, test the raw products in order to find out how they perform. The best performers will be classified higher, the lesser performers will be classified lower. The voltages will be adjusted conform the demands. In some cases better performers will be classified lower for marketing reasons instead of for their mechanical performance. AMD K6 and K7 are known for this phenomen.
Say, you have, for example, a 600E fsb 100 cpu from the above list and you run it at 800Mhz/fsb 133 and it behaves normally with stock voltage then you have a cpu that is for some reason marketed as a 600Mhz cpu but it is not fundamentally different from an 800Mhz cpu.
Another example... this 850Mhz/100 cpu runs at 1.133Mhz/133 without overvolting. The question is not if it is an 850Mhz -or- an 1.133Mhz cpu because it can do both. The branding that says that it is an 850Mhz cpu and that shows up in CPUZ is done for whatever reason that tickled the fancy of Intel at the time.
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