Microsoft released Windows 11 Build 22000.282 to Insiders in the Release Preview and Beta Channels on October 15, 2021. That update includes a fix for an L3 caching issue that can affect the performance of Windows 11 PCs with AMD CPUs. The bug can cause performance drops of up to 5% on affected systems. An earlier report indicates that a fix for the L3 caching issue could roll out to general users on October 19, 2021.
“We fixed an L3 caching issue that might affect performance in some applications on devices that have AMD Ryzen processors after upgrading to Windows 11 (original release),” says Microsoft in the release notes of Build 22000.282.
Microsoft’s release notes only specifically mention AMD’s Ryzen processors. Some other CPUs from AMD officially support Windows 11, including a handful of Threadripper chips, but it appears that the L3 caching issue only affects Ryzen chips.
A fix for a separate issue affecting Windows 11 systems with AMD CPUs could roll out later this week. The bug is related to AMD’s preferred core technology, which shifts threads to the fastest core on a processor. It can cause performance drops of 10-15%. A cumulative update to Windows 11 reportedly made the issue worse. The fix for that problem is expected in a patch from AMD on October 21, 2021.