https://wccftech.com/msi-updates-x570-motherboards-latest-amd-agesa-1-2-0-3-patch-b-bios-firmware/

MSI has released the first AMD AGESA 1.2.0.3 Patch B BIOS Firmware for its X570 motherboards. The motherboard manufacturer released the BIOS update for the trio of its X570 MEG lineup of motherboards, offering improved system performance on compatible Ryzen Desktop CPUs and APUs.

The AMD AGESA 1.2.0.3 Patch B is the official BIOS firmware that will be rolled out to X570 & B550 motherboards soon. The previous AGESA 1.2.0.3 Patch A BIOS Firmware was more of a BETA BIOS release. Much of the improvements, bug fixes, and stability will be carried over from Patch A to the Patch B BIOS.