Microsoft says that in some cases, a bug in the latest update series for Windows 11 negatively affects the copy speed.

Microsoft says the March 14 Windows 11 22H2 updates may have a negative impact on large file copying speeds. The problem mainly occurs when you want to copy a file several gigabytes in size from a network folder, although local commands would also interfere in some cases. The timing of the bug is strange as Microsoft just released a patch for a very similar issue.

Not always noticeable

It is unclear in which cases the bug rears its head. Those working with high-performance storage could experience significant inconveniences. For example, on Reddit we read the complaint of a user whose read and write speeds dropped from 7 Gbps to 3 Gbps. In many cases, network storage consists of much slower HDDs, and the SSD on an endpoint will not be able to handle such speeds. An average user probably won’t notice much of the problems.

Pending a structural fix, you can copy files through a tool that doesn’t use a cache manager. Robocopy And xcopy are not affected by the bug, although you must use it from the command line.