AMD stepping codes

[debs3759]

Do AMD stepping codes indicate different steppings (like Intel S-Specs)? I notice they only used them for a few generations of CPUs, and am unsure whether there is any point in collecting different stepping codes. I'm mostly interested in testing them with my CPUID code.

[Mr.Scott]

The AMD stepping codes are more like Intel's batch numbers than s-spec's.
AMD's OPN code would be the same as Intel's s-spec.

[debs3759]

Thanks

[Neon]

My understanding is that S-Specs indicate processors that were manufactured with the same process parameters. Intel used a design philosophy "Copy Exact" in manufacturing across their fabs, to ensure that every processor was as same as possible. This should result in high consistency, and allowed Intel to program the same electrical parameters for all processors in the same S-Spec.

AMD by contrast used a continuous improvement design philosophy that they called "Automated Precision Manufacturing". The stepping codes seem to be more like batch codes that may correspond to particular process recipes. However, processors with same stepping do not necessarily have the same programmed electrical parameters (P-State voltages and such).

Given this, and since AMD doesn't seem to have revealed much information about what the various stepping codes mean, I don't consider them to be particularly useful.

[Mr.Scott]

[CPUShack]

[debs3759]

The later ones. I have always figured the earlier ones have different CPUID codes and revisions.

[debs3759]

Also, the very latest processors don't, as far as I can tell, have stepping codes.