Microsoft has begun a massive rollout of Windows 11 update KB5006746, which fixes the problem of increased L3 cache latency in AMD Ryzen processors when running the new OS. This had a negative effect on performance, especially in some sensitive applications. Along with this AMD has released new versions of drivers for chipsets, which should help to solve another performance problem.
Hot Hardware has already tested the fixes by installing the Microsoft patch and the new AMD chipset driver simultaneously on its AMD Ryzen 9 5950X processor-based system as soon as they became available for download. Apparently, the developers really managed to solve the L3 cache issue in Windows 11. Before the driver installation and KB5006746 update, the L3 cache latency was about 32.9 ns, whereas after the fixes were downloaded, this value dropped to 11 ns. This was the same lag for the cache when the system was running on Windows 10.
Microsoft started testing the mentioned update a few days ago, making it available to members of the Windows Preview program. Apparently, the testing process did not reveal any serious problems with the package KB5006746, so the developers made it available to a wide range of users. As for AMD chipset drivers, they restore the functionality of CPPC2 mechanism used to distribute tasks to cores based on their operating frequencies.