AGESA 1.3.0.0 update artificially caps ECC memory performance on Ryzen 9000 CPUs on AM5 motherboards with ECC support

If you are running Ryzen 9000 CPUs with ECC memory on AM5 boards with ECC support, be very careful of doing BIOS upgrades. It appears the newest AMD AGESA 1.3.0.0 release has introduced an artificial cap to AM5 ECC memory speed on system with Ryzen 9000 CPUs running on motherboards from Gigabyte, Asrock, and ASUS supporting ECC memory. Some Gigabyte boards may throw post errors after installation of this BIOS. Further, once you have installed the update, it is not possible to roll back the BIOS to an earlier version to undo this change. The AGESA update limits ECC memory to 5200 mt/s, even if you are running memory capable of higher speeds. The limit isn't even a JEDEC standard, which is weird. It isn't known yet whether this was intentional on AMD's part or not, but the ASUS website contains the following description: "Starting from AGESA ComboAM5 PI 1.3.0.0, ECC-UDIMM memory speed will be limited to 5200 MT/s when paired with 9000 series CPUs". That sounds... Read more