Phoronix published a review on the Opteron vs. EPYC Benchmarks & Performance-Per-Watt: How AMD Server Performance Evolved Over 10 Years

A quote from the article:

By now you have likely seen our initial AMD EPYC 7601 Linux benchmarks. If you haven't, check them out, EPYC does really deliver on being competitive with current Intel hardware in the highly threaded space. If you have been curious to see some power numbers on EPYC, here they are from the Tyan Transport SX TN70A-B8026 2U server. Making things more interesting are some comparison benchmarks showing how the AMD EPYC performance compares to AMD Opteron processors from about ten years ago.

 Opteron vs. EPYC Benchmarks & Performance-Per-Watt: How AMD Server Performance Evolved Over 10 Years @ Phoronix