But this is for server Epyc
Fixing the recently found AMD Inception vulnerability, as shown by the first tests, leads to a huge decrease in performance.
Patching for Inception vulnerability in AMD processors can reduce performance by more than two times
The authors of the Phoronix portal tested the AMD Epyc 7763 CPU with a new firmware designed to fix the vulnerability, and found that in a number of tasks there was no impact on performance, but in some the drop turned out to be simply huge: up to 54%, that is, more than twice. Most often, significant performance degradation is recorded in applications that work with databases, code compilation, design, and image processing.
You need to understand that in this case we are talking about the server processor and the corresponding tests under Linux. How bad things are in the case of consumer Ryzen is not yet clear.