> While the parent article shows AMD Zen 5 having significantly better results in floating-point SPEC CPU2017, these benchmark results are still misleading, because in properly optimized for AVX-512 applications the difference between Zen 5 and Cortex-X925 would be much greater. I have no idea how SPEC has been compiled by the author of the article, but the floating-point results are not consistent with programs optimized for Zen 5.

The arithmetic intensity of most SPECfp subtests is quite low. You see this wall because it ends up reaching bandwidth limitations long before running out of compute on cores with beefy SIMD.