According to AMD, the performance is lower with current and older Athlon/Epyc/Ryzen processors when Windows 11 is used instead of Windows 10. The decrease in performance amounts to 3 percent to 15 percent, depending on the software and chip used.
Windows 11 impacts gaming performance with Ryzen processors is due to an increase in L3 cache latency. Both AMD and Microsoft are aware that L3 cache latency on Windows 11-compatible Ryzen processors increases by up to three times. This negatively impacts games.
Another issue is that AMD’s “preferred kernel” feature does not work as advertised. Preferred Core maps applications to the fastest core on the chip, which can cause significant drops in performance with chips of 65W or more.
Fortunately, Microsoft and AMD are already working on an update to address performance issues with AMD processors, which will be released via Windows Update. For all those Ryzen users out there, it is better to wait for the patch before making the jump to Windows 11.