Slower SMB read performance for large files in 22H2

Situation after KB5026372 is *MUCH* better but still there's something wrong with RSS/Multichannel. As long as it is enabled we see slower speeds all across and about 50% of the performance we had on the network prior to the issue. We also see strange ramping up of speed when traffic is from client to server. Without RSS/Multichannel we now see the expected performance after KB5026372. We use Intel X710-DA2 adapters all across, on fiber.

It's not fixed as far as I'm concerned. It's incredibly obvious that it isn't when my copy speeds to my NAS from desktop to NAS are quicker than NAS to desktop. Not to mention, FTP is much zippier. For what it's worth I do have KB5026372 installed. 

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Lance Longreen 

 

So tested. As others like @Nodens has also seen the issue is NOT fixed yet even with latest patches/KBs

 

And with the new UEFI vulnerability we cant use 21H2 more for long...so Microsoft @Ned Pyle understand this is in the kernel but really at this point and especially with the UEFI vulnerability meaning we have to use latest 22H2 You at Microsoft needs to set aside the necessary resources and get this fixed !

 

Its so serious that one cant copy files at 10gig let alone 25gig or higher speeds without the speed tanking considerably !

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WHAT IS YOUR PROBLEM, Lance?  SHEESH!

the problem appears to be FULLY FIXED with the May 2023 https://support.microsoft.com/help/5026372 update.
the slow copy problem is no longer being mentioned in the "known issues" section of MS support article 5026372.

And I see these comments from https://www.neowin.net/news/windows-11-may-patch-tuesday-update-kb5026372-arrives/ that Microsoft revised some of their support articles, removing the copy problem.

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Wow! Could it be? Have they finally fixed the slow copy of large files over the network??? I certainly hope so, I've been waiting for that for months! It isn't in the known issues section...

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Well, ATM I'm transferring an 80GB ISO to another drive on my network and it's fluctuating between 25 MB/s and 54 MB/s ...a little bit before that I transferred a 5GB file to a different drive and was getting a solid 119 mb/s.

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I noticed that Microsoft silently removed the issue also from past Patch Tuesday KB pages, it's just gone and it was there last month and a few months before that. Weird...

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so install the KB5026372 or newer update and stop complaining about the copy problem not being fixed, Lance.
it's now over and done with as many 22H2 users who have installed KB5022913 or later patches have confirmed the problem has been resolved.

heck, MS quietly revised https://support.microsoft.com/help/5022845 around early May to mention that the copy problem was "addressed" in KB5022913.

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Copying large multiple gigabyte (GB) files might take longer than expected to finish on Windows 11, version 22H2. 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.Windows devices used by consumers in their home or small offices are not likely to be affected by this issue.

This issue is addressed in https://support.microsoft.com/en-us/topic/february-28-2023-kb5022913-os-build-22621-1344-preview-3e38c0d9-924d-4f3f-b0b6-3bd49b2657b9. 

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so thus, it turns out Ned Pyle was right all along and the Microsoft tech people who publish/write those support KB articles were super slow in recognizing the slow copy problem being fixed with KB5022913 & newer updates and have updated several past support articles for past updates from KB5023706 to KB5025305 to no longer mention that problem.

So tested. As others like Nodens has also seen the issue is NOT fixed yet even with latest patches/KBs

And with the new UEFI vulnerability we cant use 21H2 more for long...so Microsoft NedPyle understand this is in the kernel but really at this point and especially with the UEFI vulnerability meaning we have to use latest 22H2 You at Microsoft needs to set aside the necessary resources and get this fixed !

Its so serious that one cant copy files at 10gig let alone 25gig or higher speeds without the speed tanking considerably !

NedPyle please let us know where this is at the kernel team and what is the plan to remedy this serious bug that's been going on for 8 months now.

@ community maybe its time to use our connections at various large tech sites to put some pressure on. Frankly in its current state Windows 11 cant be used for any serious file copy or file editing on any enterprise or even SMB targets/NAS/SAN ! 

Karl-WEissue still present on 22621.1555 although somewhat less severe. RSS is also still broken (disabling RSS actually increases performance).

We're not talking about unexpected performance drops, we're talking about a very specific issue here that is apparently only slightly mitigated. Even Microsoft is aware as it is still present in known issues on KBs.
We're using SMB with Linux server, serving VMware Workstation images to Windows 11 Client workstations (we're doing driver and low level software engineering and we test and debug on said images) and performance is still abysmal compared to what it was with the exact same infrastructure before the issue manifested.

Taking an educated guess, I'm willing to bet that commits in the kernel triggering this can not be reverted due to downstream fixes/features depending on them and fixing the actual issue is complicated. We just received a bandaid solution. It is still very disappointing that this is *still* not prioritized after so many months.

What's your situation on this everyone.

Another sidenote.

There's a by design issue for sustained (talking about minutes!) writes on VMware OSA (VSAN / VXRail) RAID5, according to Dell documentation, which is significantly dropping perfomance. This is fixed in ESA (VSAN 7)

Also watch out for the VSAN 250 GB chunk vmdk rule (wonder how S2D handles it) and internal placements on HDD in the pool and the effect of storage policy on raise stripe sets. The effects are huge! 

We saw massive decrease of perfomance from 600 MByte / s down to 8 MB/ s importing SQL DB or SMB traffic.

None of these related to this issue NedPyle posted about.

Just mention this as there are more reasons for "unexpected" performance drops. 

So still no update ? With the latest KB it's still not working for me also not with fresh install.

Does anyone have it working with filecopy over network after the latest kb ?

So....is it working now for file copy over network from NAS to Win11 client yes or no ? (That message in latest 'fix') makes it sound like it's not fixed at all

Nodens I'm in agreement with you that it's not for everyone and shouldn't be applied haphazardly.  It applies more to those with 10Gbit/s or faster ethernet connections with dedicated adapters.  I'm not sure if your post was directly at me specifically or in general.  It did come off as a little bit condescending at first glance, just fyi. 

Regardless, for all those that may be curious about trying it, Nodens warning is apropos and should be heeded by those curious.  Just because it solved my issues doesn't mean it'll solve yours.

I would not apply that optimization script blindingly specially if you don't understand what it is doing (and if you do, you don't actually need it as you can apply said tweaks yourself on a need to do basis).

It applies a bunch of network stack options blindingly that are not always good to apply. For example it disables interrupt moderation entirely which, in quite a few use cases, will produce quite the opposite effect and can and will cause latency issues with any real time applications (eg prof audio/video).

That said, KB5022913 Preview still has the issue listed in known issues which probably means that the kernel fix is not included in the preview and we should wait for the full update.