Ned Pyle, a top program manager at Microsoft, wrote that there is a performance regression in Windows 11 Update 2023 (23H2) when copying files from a remote computer using the SMB (Server Message Block) protocol. The performance success was discovered by Petri.com.
It is not entirely clear whether copying files will be slower when downloading them from a remote server or simply accessing them from a remote PC. Microsoft doesn’t seem to know very well either. “The problem isn’t really in the SMB code, so I can’t yet provide an ETA for a permanent fix; SMB is just the most likely scenario to be noticed,” Pyle wrote. “You can see this behavior even with local file copies that don’t use SMB. We are working with another team to understand this and come up with a permanent solution.”
The slowness seems to manifest itself when copying or downloading “large” files (several gigabytes) from a remote machine to a PC running Windows 11 2023 Update (23H2). Files that are copied to another PC that does not run 23H2 will not see the slowdown, wrote Pyle.
There is a workaround. “[U]if robotcopy or xcopy as /J (Unbuffered I/O),” wrote Pyle, which will return performance to expected levels. Pyle provided an example of the code:
robocopy \\someserver\someshare c:\somefolder somefile.ned /J
Last week, Microsoft reported a printer bug that manifested itself when printers were unable to communicate their advanced features to a host PC, which prevented those features from working. Microsoft has blocked users with the issue of upgrading to 23H2.