The Performance Impact To AMD Zen 2 Compiler Tuning On GCC 9 + Znver2

Here is the radar chart to get started in immediately getting an idea for the situation. In some workloads, the znver1 vs. znver2 tuning on Ryzen 9 3900X can yield a few percent difference.

With this FFT benchmark, using the Znver2 target allowed about a 4% boost to the performance.

In the SciMark micro-benchmarks that are very sensitive to compiler changes, using Znver2 allowed an 18% boost to the performance over Znver1 target on the 3900X CPU.

But in some workloads like the TSCP chess benchmark, using Znver2 actually regressed the performance.