AMD Family 19h CPU Microcode Updated (2023-10-19 Rev)

AMD today published a new CPU microcode revision for Family 19h processors, which include Zen 3 / Zen 3+ / Zen 4 processors. As is sadly standard, no change-log is provided.

AMD Family 19h CPU microcode 2023-10-19 was added today to Linux-Firmware.Git, the de facto location where CPU microcode/firmware binaries are housed for easy integration by Linux distributions and other software vendors.

The commit updating the CPU microcode simply notes, "Update AMD cpu microcode for processor family 19h" which is standard for the AMD microcode updates with very rarely outlining what fixes, security updates, or other changes are made. The updated CPU microcode is automatically applied at boot-time on Linux systems or can alternatively be late-loaded as well for those wishing to avoid the reboot/down-time.

The new microcode is the first AMD Family 19h update since August when AMD released updated CPU microcode for addressing the Inception vulnerability. Today's microcode push falls outside of Patch Tuesday and there are no new security bulletins from AMD this week on the CPU side, so hopefully this amounts to just a routine update for addressing functional issues or other refinements. In any event I'll be trying out the new CPU microcode on AMD Zen 3/4 servers to look-out for any changes or performance differences.