Microsoft has finally addressed a known issue causing significant performance hits when copying large files over SMB after installing the Windows 11 2022 update.
The bug was fixed with the KB5022913 February 2023 non-security preview update released on February 2022, which also introduced newly announced Moment 2 features.
“This update addresses an issue that affects copying from a network to a local drive. Copying is slower than expected for some users,” Microsoft said.
The fix comes after Microsoft’s Ned Pyle explained in October that “there is a performance reduction in 22H2 when copying larger files from a remote computer down to a Windows 11 computer or when copying files on a local drive.”
While Redmond did not share details on the actual performance decrease, according to user reports, the time needed for file operations on affected systems could more than double in some conditions.
“You are more likely to experience this issue copying files to Windows 11, version 22H2 from a network share via Server Message Block (SMB) but local file copy might also be affected,” Microsoft added in a September update to the KB5017389 preview update support document.
Two months later, in November, the company began testing a fix that rolled out to some systems enrolled in the Windows Insider program running Windows 11 Preview Build 25252.
Workaround available
KB5022913 allows Windows admins to test improvements and bug fixes that will roll out to all Windows users with next month’s Patch Tuesday.
However, this one is optional and does not contain security updates. You can only install the optional KB5022913 update by clicking the ‘Download and install’ button after checking for updates from Settings > Windows Update.
You can also manually download and install the KB5022913 update for your platform from the Microsoft Update Catalog.
Microsoft has also shared a temporary fix that affected customers can use to workaround the file copy performance hit.
Users can mitigate the known performance issue impacting file copying over SMB with the help of file copy utilities that don’t employ cache manager (buffered I/O).
Two of the available options include the built-in robocopy and xcopy tools with the template commands listed below:
robocopy \someserversomeshare c:somefolder somefile.img /J
OR
xcopy \someserversomeshare c:somefolder /J