How much do they hurt, and how to opt out.
www.tomshardware.com
Take it with a grain of salt but more or less matches what I have seen on my system.
Tom's tested Intel's 10700K and 11700K and AMD's 3800X and 5800X.
TLDR: Intel's 10th and 11th generation CPUs and AMD's Zen 2/3 CPUs tank about 5% average on gaming, with some games a little higher and others a little lower (with GTA V on DX11 being the weird one that barely tanked 1% on all tested CPUs). 3DMark seem to tank even less, the difference might as well be non-existent, though VRMark seems to go back to around 5% performance hit.
Average application performance tanks very little on AMD. Zen 3's performance is virtually unaffected, and Zen 2 takes a mere 1% hit on average. On Intel, the 11th gen takes barely 1% hit, but 10th gen takes a bit of a larger hit, 4%.
All of those values are averages, you'd better check out Tom's article if you want more details.
Figures I'll add this here too
Windows® 11 Performance Variation in Certain Applications on Compatible AMD Processors
Article Number
PA-400
This documentation provides information on known performance impacts reported on Windows® 11 when running
compatible AMD processors on certain applications.
Issue Description
AMD and Microsoft have determined that
compatible AMD processors may exhibit reduced performance in certain applications when running Windows® 11.
Known Performance Changes | Impact | Resolution |
| 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.
|
Additional Information and Workaround
AMD and Microsoft are actively investigating these known issues for resolution via software updates. This knowledge base article will be updated to include version numbers and delivery vehicle(s) when they are available. In the interim, customers using compatible AMD processors affected by these issues may continue to use a
supported version of Windows® 10.
