AMD has said that some models of processors have performance problems after upgrading to Windows 11. The general impact is between 3-5%, and in some extreme cases the impact is as high as 10-15%. In cooperation with Microsoft, AMD’s newly released Ryzen chipset driver has been repaired again.
The release notes indicate that the latest driver update restores the expected functionality and behavior of UEFI CPPC2 in Windows 11 build 22000.189 (or later) on AMD processors. This page also tells us which chipsets and processors AMD supports when installing Windows 10 and Windows 11. AMD has a dedicated page for solving problems related to performance changes of compatible processors on Windows 11. You can view it here.
However, not all problems have been resolved. Known issues include custom installation failures, problems with non-English operating systems, and unintentional pop-up messages. To learn more, you can click here to view the release page.