AMD EPYC Rome Still Conquering Cascadelake Even Without Mitigations

Obviously for workloads bound to user-space without any or much kernel interactivity and not stressing areas affected by these mitigations, the performance is unchanged when disabling these mitigations. In cases like NPB and NAMD, EPYC Rome simply dominates over the current-generation Intel Cascadelake processors.

In some Java workloads, there is a small performance boost out of disabling these mitigations. In these particular Renaissance benchmarks, the Java tests are single-threaded and thus Intel CPUs coming out ahead regardless due to their higher clock frequencies and the rest of the CPU cores simply idling during these particular benchmark runs.

Rome did see a 3% boost in performance for John The Ripper when booted with mitigations=off, but even with mitigations, the AMD EPYC 7742 2P server dominates against the non-AP Intel Cascadelake.

Compilation workloads tend to be one of the real-world tests showing impact from these different CPU vulnerability mitigations over the past year and a half. The mitigations remaining with these current-gen CPUs do still cause a slight impact to the compilation speed of GCC due to the I/O involved, but even with an unmitigated Intel Cascadelake server, it's still by no means competitive against the EPYC 7742 2P top-end processors.