If you assume that most real customers use a regular compiler like GCC or Clang then benchmarks using tuned compilers like AOCC (never heard of it before today) or ICC are unrepresentative. However, the proper way to make such a comparison would be to run benchmarks using GCC on all the chips, not to apply magic derating factors. Shame on Ampere for such voodoo benchmarketing.

Oh, and don't miss the 3.0 vs. 3.3 GHz.