Mass file copy speed starts fast but slows down, then fast again

Discussion in 'Windows 10' started by eemuler, Sep 23, 2019.

  1. RJARRRPCGP

    RJARRRPCGP MDL Senior Member

    Feb 24, 2010
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    Even an early-gen Intel SSD that I once had, easily about 10 years old, IIRC, had a higher sequential write speed than that, but it was an early-2000s-to-mid-2000s-HDD-like 45 MB/s or similar. And 10 MB/s is like a better USB 2.0 drive, LOL.
     
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  2. eemuler

    eemuler MDL Senior Member

    Jul 31, 2015
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    Until the 100% disk usage bug kicks in, this SSD gives around 500 MB/s. CrystalDiskMark is good for a SATA drive, especially in this price range.

    CDM D.png
     
  3. RJARRRPCGP

    RJARRRPCGP MDL Senior Member

    Feb 24, 2010
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    Is Windows 10 reporting a problem with the ATA port and storahci.sys, in the event log, known Windows 10 bugs.
     
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  4. eemuler

    eemuler MDL Senior Member

    Jul 31, 2015
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    No. Didn't see any such errors in the event viewer, in fact seems there were no related errors, except right at the start when I booted after installing the new drive - when it was unformatted and unintialised.
     
  5. Micro

    Micro MDL Member

    Apr 26, 2009
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    #47 Micro, Sep 27, 2019
    Last edited: Sep 28, 2019
    I solved this problem locally by adjusting my working set cache to 1/2 of my memory + 1gb.
    Here it also affected USB3 transfers, dropping from USB3 speeds down to (and staying at) USB2 speeds after 1gb was transferred.
     
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  6. eemuler

    eemuler MDL Senior Member

    Jul 31, 2015
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    @Enthousiast - I'm ready to do the clean install thing to see if that will fix this, but as 19H2 is expected in less than a week, should I wait for it or do a clean install of 19H1 now and then upgrade to 19H2?
     
  7. bfoos

    bfoos MDL Guide Dog

    Jun 15, 2008
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    19H2 is available now, just not GA yet. No reason to install 19H1 and upgrade to 19H2. If you are going to clean install, you may as well just install a 18363 build.
     
  8. BAU

    BAU MDL Addicted

    Feb 10, 2009
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    Just hit this 100% disk usage bug yesterday on version 1903.
    It made the system bloody unresponsive for minutes - nothing worked, barely could launch task manager, and disk i/o reported was mere kilobytes during lock-ups.
    But then it recovered fully, only to break again half hour later. I know too well these symptoms of drives getting bad sectors or pierced cables, so it got me a little worried.

    It was late, I had no time to spare investigating it so I've installed a 1709 version I had around, and everything works perfectly. Just MS things..

    In retrospect, what I was doing at that time was basically run many cmd / powershell scripts some with elevation, some without, with little to none file I/O,
    which leads me to believe the lead culprit for this particular system was - no shock there - Windows Defender & other "protections".
    Note that automatic sample submission, cloud delivery and real-time protection were all disabled via UI (since with them on scripts were running almost half the speed FFS!)
    Yet I've seen glimpses of Defender processes in the limited tracing back I've attempted.
    My guess is that UAC (do not dim my desktop) along with SmartScreen (even if working on locally created files) and other "protections" / mitigations / whatever could trigger this bug.

    I'm not gonna install Avira just yet, but let the OS update and see if I hit the bug again doing more of the same.
     
  9. eemuler

    eemuler MDL Senior Member

    Jul 31, 2015
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    100% disk usage by Windows File Explorer. I think some 'feature' is misbehaving. Like preview panel, file information, indexing, thumbnails, yada, yada, yada. I'm trying to turn off everything I can think of, but there are a hell of a lot of them. Anyway, I should be running a clean install of 19H2 tomorrow, so we'll know if that fixes it or not.

    On a related note, I ran O_O ShutUp 10 and turned off a bunch of stuff there. It didn't fix the issue I'm having, but now there are a lot more errors in the event logs as various services are not responding as expected. I think O_O is not doing it right - Group Policy editor should be the tool of choice for turning stuff off.
     
  10. RJARRRPCGP

    RJARRRPCGP MDL Senior Member

    Feb 24, 2010
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    Sounds like the dreaded "Windows 10 ATA port reset and storahci.sys bug", which I first noticed in 2016. It's ironically more likely to occur with SSDs than with platter drives! Please check the event log. I bet there's also a message waiting for you about the device being retried. Sounds like Microsoft didn't kill that bug!
     
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  11. Yen

    Yen Admin
    Staff Member

    May 6, 2007
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    Did you install the official 1709 ISO or one that had any updates included until EOS?
    Did you run default AHCI driver from MSFT?
    Just out of curiosity.

    Well, this can be easily evaluated trying Intel AHCI driver instead of...or to try to fix it yourself. It has been fixed like that.....

    Code:
    Windows logo key + X -> Device Manager
    IDE ATA/ATAPI Controllers -> Double-click AHCI controller
    Driver -> Driver Details -> If you can see storahci.sys there, it is time to fix the bug in question
    Details -> Property -> Device instance path -> Write down/ copy the path starting from PCI\VEN
    Windows Key + X -> Search box -> Type regedit -> Registry Editor
    Proceed to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\PCI\<AHCI Controller>\Device Parameters\Interrupt Management\MessageSignaledInterruptProperties
    (<AHCI Controller> refers to the path from the Step 4)
    MSISupported key -> Set “0” as its value
    Restart your computer
     
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  12. eemuler

    eemuler MDL Senior Member

    Jul 31, 2015
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    Okay, I did a clean install of 1909 and did the Windows update thing, then installed the latest available drivers. 18363.356
    Sadly, the problem is still there. It seems to have improved a bit - it managed to transfer 80% of 18 GB at full speed before slowing down to 11 MB/s.

    Very interesting post by @Yen but I'm not seeing any storahci.sys. Bummer - I really thought I saw some light at the end of the tunnel.

    1909.png
     
  13. Enthousiast

    Enthousiast MDL Tester

    Oct 30, 2009
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    My similar problem ended when i checked the system ssd with magician and it offered a firmware update, not seen anything weird since (knock on wood :D) + i enabled rapid mode.
     
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  14. Enthousiast

    Enthousiast MDL Tester

    Oct 30, 2009
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    All that trouble to be able to spam every post you do?
     
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  15. RJARRRPCGP

    RJARRRPCGP MDL Senior Member

    Feb 24, 2010
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    Please check the Windows event logs. (With what is or was called Event Viewer) And look for ominous messages about the ATA port and/or the driver being used.
     
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  16. eemuler

    eemuler MDL Senior Member

    Jul 31, 2015
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