Microsoft Fixes Perf Issues in Windows 11 for Large File Copying over SMB with KB5022913 Update

Microsoft has fixed a known issue that affected the performance of large file copying over Server Message Block (SMB) protocol with the Windows 11 2022 update.

The bug was addressed with the KB5022913 February 2023 non-security preview update, which also introduced Moment 2 features. According to Microsoft, the update has resolved the slow copying of files from a network to a local drive that some users were experiencing. Previously, Microsoft's Ned Pyle explained in October that the performance reduction in Windows 11 2022 was affecting users when copying large files from a remote computer or on a local drive. Although Microsoft did not disclose the actual performance decrease, some user reports indicated that the time needed for file operations on affected systems could more than double in some instances.

The issue was more likely to occur when copying files to Windows 11, version 22H2 from a network share via SMB, but local file copying could also be affected. The company began testing a fix in November, which rolled out to some systems enrolled in the Windows Insider program running Windows 11 Preview Build 25252. However, affected customers can still use a temporary workaround to mitigate the known performance issue impacting file copying over SMB. Users can use file copy utilities such as robocopy and xcopy tools, which don't employ cache manager (buffered I/O), to avoid the performance hit. The KB5022913 update is optional and can be installed by clicking the "Download and install" button in Settings > Windows Update, or by manually downloading and installing it from the Microsoft Update Catalog.