A Look At How The Linux Performance Has Evolved Since The AMD EPYC Launch
For many different workloads, going from Ubuntu 17.04 to 19.04 generally meant nice out-of-the-box performance increases for the AMD EPYC server while to a lesser extent the Linux 5.2 kernel. Disabling Spectre mitigations generally shows just tiny performance differences except for in select cases like the synthetic kernel benchmarks, Glibc interaction, and other workloads with high kernel interactivity.
The time to perform a context switch was made slower by Linux 5.1~5.2. But the AMD EPYC context switching speed with Spectre mitigations is now still much better than a fully mitigated Intel Xeon box.