Slower SMB read performance for large files in 22H2

slowdown SMB copy problem continues (as in not fixed), even with newly released KB5019980 update for Win11 22H2 as the problem is still noted there.

Dear Microsoft team when will this severe bug be fixed ? Frankly this has taken too long to fix at this point. Please update us on when we can expect the fix ? Thank You

It shows a lack of concern for this flagship desktop OS.

Thanks for letting me know and bringing the temporary solution. 

I can't share too many details yet, but we know exactly where it is getting slower in Kernel, nothing to do with SMB or compression. 

See updated note in the blog post. The preview fix for this issue is in Windows 11 Insider Preview Build 25252

The permanent production fix will come in a normal monthly cumulative update after this is validated. As I've mentioned before, the fix is not in SMB, and since it's not a component I own, I don't have further details on timing. 

I had not joined this conversion until now because I trusted that Microsoft was actually working on a fix for this. However, I need to chime in here and say that this issue is NOT fixed in Windows 11 Insider Beta build 22623.1245, as claimed in Microsoft's release notes:

• We fixed an issue that affected copying from a network to a local drive. Copying was slower than expected for some users

After fighting with this issue for almost 5 months now, I was eager to test out this fix in 22623.1245. Unfortunately, I'm still seeing very slow file transfers moving data from my 10GbE-connected server on this build, on the order of 50-60% of expected performance for gigabit clients and 30% of expected performance for 10GbE clients. 

That I found effectively no change in performance in this build was the last straw, so I made the decision to roll back several PCs with wired LAN connections to Windows 10. This was hours of my time that I did not need to spend. 

I get that most consumers on wireless LANs will never see this issue, but lots of businesses use Windows on wired LANs and depend on fast file transfers. We upgraded to 10GbE a couple years ago for better performance. Seeing this investment undermined by Windows 11 is truly disheartening.

If think if this had happened "back in the day", Dave Cutler, Moshe Dunie, or Jim Allchin would have fired the team responsible.

Please Microsoft, take this seriously.

Can also confirmed that its NOT fixed in both 22621.1245 and 22623.1245 (tested both just for the sake of it) this file copy bug is NOT fixed. To be honest this is a highly critical bug, i cannot believe ostd still not fixed even You write it is in your insider release notes. Microsoft it is really time to step it up ! @ned can we please get some official reply to why it's still not fixed even in latest insider builds?

Any update on this ? With latest update from last week i still have this issue across several PCs

23h2 all patched-up and a fresh synology 923+ (via intel x550-t2). SMB3 copy from NAS to PC is at 650MBytes/s, but copy from PC to the same NAS is at 1,2GBytes/s (I've got SSD's raid0 in NAS). Thanks God I found this thread because I was going crazy over it.