Get the latest tech news
AMD Disables Zen 4's Loop Buffer
A loop buffer sits at a CPU's frontend, where it holds a small number of previously fetched instructions.
AMD's Zen 4 optimization guide makes no mention of the loop buffer and only suggests keeping hot code regions within the op cache's capacity. After I updated my ASRock B650 PG Lightning to BIOS version 3.10, hardware performance monitoring indicated the frontend no longer dispatched any micro-ops from the loop buffer. Perhaps some more mainstream tech outlets will figure out AMD disabled the loop buffer at some point, and do testing that I personally lack the time and resources to carry out.
Or read this on Hacker News