Windows 11 PRO 22H2 Slow SMB Download

Question

I use Windows 11 PRO 22H2 to transfer files to my NAS server.

The transfer speed of big files (3GB+) from Windows to NAS is on expected level. The transfer speed is about 260+ MB/s on 2.5 Gbps connection, if connection is 2x2.5 Gbps (multichannel SMB is ON) the transfer speed is about 550+ MB/s. It works more or less OK.

BUT, the transfer speed of big files (3GB+) from NAS to Windows is very low. The transfer speed is about 140 MB/s (stable) on 2.5 Gbps connection and 280-290 MB/s (stable) on multichannel SMB connection (2x2.5 Gbps). So, reading files from NAS is 2 times slower than writing the same big file(s) to NAS. I use different Windows Clients to transfer files e.g. Windows File Explorer or Windows Commander. The results are more or less the same, the reading operation is about 2x slower than writing operation.

Windows Task Manager does not report CPU, memory, network or destination disk overload, a lot of free resources.

Windows 10 Home installation from scratch + newest NICs PC drivers -> OK, no SMB multichannel transfer issues, about 550-560 MB/s transfer speed for uploading and downloading too !

Windows 11 Home installation from scratch + newest NICs PC drivers -> Not OK, still problem with SMB protocol and SMB multichannel speed transfer (downloading).

******It seems to be problem with SMB on Windows 11.******

Answer 1

Confirming the problem, why is Microsoft doing nothing about it!