As reported a short while back, AMD has officially rolled out the latest ASESA 1.2.0.1 firmware aimed at improving the L3 cache performance of the Ryzen 5000 processors along with some additional fixes for the Vermeer lineup. The highlights of the release include a fix for false SMART errors on Hynix NVMe SSDs, issues with detection of M.2 based SATA drives, and improved stability when disabling cores on a Ryzen 5 5600X or 5800X using Ryzen master.
With older version AGESA 1.2.0.0, the L3 cache bandwidth was severely limited on certain boards. As you can see in the below screenshot, the L3 read and write bandwidth were just under 300GB/s and 350GB/s, respectively with the older firmware:

With the update, the same are pushed to over 1,000GB/s and 848GB/s, respectively, an increase of around 3x. It’s unclear whether every processor was affected by this bus and how much of an impact did it have on performance across various workloads, but there should certainly be a notifiable uplift in many applications.

MSI has already rolled out the AMD AGESA 1.2.0.1 Firmware on its following 500-series motherboards: