The Ryzen 5 7600X is one of the best CPUs for budget consumers. However, AMD's AGESA ComboAM5PI 22.214.171.124 firmware with SMU 84.79.204 unintentionally disabled cores on Ryzen 5 7600X chips with dual-CCD designs. The revamped AMD firmware with the new SMU 84.79.210 has seemingly fixed this problem.
The previous firmware caused a performance degradation on dual-CCD Ryzen 5 7600X samples because it deactivated Core0. In some cases, the system outright didn't post because the firmware tried to boot off a single CCD. Presumably, other Ryzen 7000 chips were also affected. In any event, AMD quickly caught on to the problem, and its partners, including ASRock, Asus and Gigabyte, removed the problematic firmware from their respective X670 and B650 motherboard support pages.
However, it looks like the issue was a walk in the park for AMD to fix. According to hardware leaker chi11eddog (opens in new tab), the chipmaker has already distributed the updated firmware to its partners. The AGESA version remains the same; however, AMD updated the System Management Unit (SMU), which manages various aspects of the processor, such as clock speeds, voltages, and power limits.
You can distinguish the new firmware from the prior one by the version of the SMU. The old firmware had SMU 84.79.204, whereas the new firmware leverages SMU 84.79.210. MSI has deployed the latest firmware for the company's AMD 600-series motherboards. Mind you, the firmware is still in the beta phase, so upgrade at your own risk.
The AGESA 126.96.36.199 microcode is important as it supports AMD's recently-announced Ryzen 7000 non-X chips, such as the Ryzen 9 7900 and Ryzen 7000 X3D parts with 3D V-Cache. The former is already available; meanwhile, the latter arrives on the retail market in February. Therefore, AMD still has time to work out the kinks and prime the firmware for Ryzen 7000 X3D's debut.