Via a a new support page, AMD acknowledged the issue. The chip designer is working on a fix to resolve Windows 11 performance issues. The patch is expected to be out later this month.
AMD identified two issues:
Measured and functional L3 cache latency may increase by ~3X.
- Applications sensitive to memory subsystem access time may be impacted.
- Expected performance impact of 3-5% in affected applications, 10-15% outliers possible in games commonly used for eSports.
- A Windows update is in development to address this issue with expected availability in October of 2021.
UEFI CPPC2 (“preferred core”) may not preferentially schedule threads on a processor’s fastest core.
- Applications sensitive to the performance of one or a few CPU threads may exhibit reduced performance.
- Performance impact may be more detectable in >8-core processors above 65W TDP.
- A software update is in development to address this issue with expected availability in October of 2021.