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Windows 10 Pro local file copy speed limits

Anonymous
2021-04-10T12:38:28+00:00

Hi! My question is about potential file copy speed limits in windows 10 Pro.

I am going to ask the question first in an effort to save some reading time for all:

Doesn't matter if I use standard windows copy or use TeraCopy I still get this hard speed limit on file copy at 2.1GB/sec (that's GigaBytes).  Using very large (or small) files.

Is there any limit in Windows Pro or the file copy software ?

Is there a limit related to AMD implementations running windows ?

Am I hitting some microsoft NVME driver limits I should be aware of ?

My configs:

CPU: AMD Ryzen Threadripper 3990X 

MOBO: ASUS ZENITH II EXTREME ALPHA

RAM: CORSAIR VENGEANCE PRO RGB 128GB (8 x 16GB) DDR4 3200 @3200

SSD: Non-Raid NVME SAMSUNG 980 PRO M.2 2280 2TB

SSD: Non-Raid NVME SAMSUNG 980 PRO M.2 2280 2TB

SSD: Non-Raid NVME SAMSUNG 960 PRO M.2 2280 1TB

SSD: Non-Raid NVME SAMSUNG 960 PRO M.2 2280 1TB

System: Windows 10 Pro x64 VER 20H2 OS build 19042.870

Latest Samsung NVME drivers for 960 PRO (none available for the 980 Pro)

Latest Microsoft NVME drivers for Windows 10

Not running an additional Anti-virus, only Windows Defender

Test tools:

A 19GB file, a 6GB file, and a 2GB file.

CrystalDiskMark 8.01 64-bit benchmarks

AS SSD benchmarks

Windows file copy

TeraCopy for windows

HD Tune v2.55

So I setup the first 980 Pro NVME in first slot M.2_1 as recommended by asus. I then benchmark and get:

CrystalDiskMark 8.01 64-bit benchmarks at 7GB/sec read and 5GB/sec write (expected)

AS SSD says that raid has 7GB/sec read speed and 5GB/sec write speed (expected)

I copy a file locally from the same disk and get 2.1GB/sec.

I copy a file locally from a second 980 PRO setup in M.2_2 and get 2.1GB/sec

I copy a file locally from a RAMDISK and get 2.1GB/sec.

I copy a file locally, simultaneously on both of the 980 PRO drives and get 2.1GB/sec each (total of 4.2GB/sec of simultaneous throughput).

I setup both (2x) 980 Pro drives (using slots M.2_1 & M.2_2) with a software stripe RAID via Disk Management and dynamic disks and run the benchmarks.  I get:

CrystalDiskMark 8.01 64-bit benchmarks at 11.4GB/sec read and 10GB/sec write (expected)

AS SSD says that raid has 10GB/sec read speed and 10GB/sec write speed (expected)

I copy a file locally from the same disk and get 2.1GB/sec.

I copy a file locally from a second 960 PRO windows software RAID setup in DIMM.2_1 and DIMM.2_2 and get 2.1GB/sec

I copy a file locally from a RAMDISK and get 2.1GB/sec.

I copy a file locally from a RAMDISK to RAMDISK and get 2.1GB/sec.

I setup all drives with a software stripe RAID via Disk Management and dynamic disks and run the benchmarks with all 4 disks in the following slots:

M.2_1 – 980 Pro 2TB

M.2_1 – 980 Pro 2TB

DIMM.2_1 – 960 Pro 1TB

DIMM.2_2 – 960 Pro 1TB

CrystalDiskMark 8.01 64-bit benchmarks at 14.4GB/sec read and 14GB/sec write (expected)

AS SSD says that raid has 14GB/sec read speed and 12GB/sec write speed (expected)

I copy a file locally from the same disk and get 2.1GB/sec.

I copy a file locally from a RAMDISK and get 2.1GB/sec.

I copy a file locally from a RAMDISK to RAMDISK and get 2.1GB/sec.

Doesn't matter if I use standard windows copy or to use TeraCopy I still get this hard limit of file copy at 2.1GB/sec.

Using some software to open or save files, such as Photoshop, benefit from faster than 2GB/sec read and writes.  Have not run exhaustive tests on this yet.

What else I have tried:

1, 2, 3, 4 disk combinations.

RamDISKs combinations

Chipset updates and rollbacks to previous versions.

Changing RAM speeds to basic speeds 2133, 2333, 2666, 2800, 3000 (no change in file copy performance)

Changing Infinity Fabric speeds to 1200, 1600, 1800

Changing PCIe versions in BIOS to PCIe 4.0, 3.0, 2.0

Disabling every power saving features in BIOS

Disabling Windows Defender Real Time protection

Is there any limit in Windows Pro or the file copy software ?

Is there a limit related to AMD implementations in windows ?

Am I hitting some microsoft NVME driver limits I should be aware of ?

I know that Samsung SSD’s have a DRAM cache (& 980 Pro - Intelligent TurboWrite 2.0) that can be exhausted and then the speeds drop down to the SSD’s speed capacity that are in the range of 1700MBps for each drive on the 1TB and 2TB versions of the PRO series.  I should still be able to get 3.4GBps at a minimum using 2 drives.  At least 5GBps on all 4 drives.

How can I speed up file copying ?

Thanks in advance for the help.

Windows for home | Windows 10 | Performance and system failures

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  1. Anonymous
    2021-06-26T20:53:45+00:00

    Amen !  Finally a potential solution.  I will try this shortly.

    Also, from reading the FastCopy website, it looks like this is likely a windows issue.  Pointing either to the Microsoft Foundation Class (MFC) Library, or the fact that windows explorer seems to uses a limited number of threads for File Copy functions [in my tests some threads weee stuck at 99% during copy while others were unused].

    I’m so surprised at how we engineer hardware with such huge capacities only to limit it by software.   What a shame.

    Will report back on my performance.

    Thanks again.

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  2. Anonymous
    2021-06-24T21:08:30+00:00

    I have been experiencing similar limitations with File Explorer copies on fast NVMe (PCIe Gen4x4) drives but found a solution.

    I got speeds between 2.0-2.8GB/s no matter how fast drives I was using.

    Some SSDs can even exceed 5GB/s sequential writes in Crystal Diskmark. (e.g. WD Black SN850). Also tested Seagate FireCuda 520, Corsair MP600.

    I have tested multiple platforms (X299, TRX40, X570, Z590).  And all of them have similar limitations 2.0 -2.8GB/s using File Explorer.

    AMD TRX40 and X570 are the only platforms with multiple Gen4x4 ports and the highest copy speed with large files in File Explorer peaked at 2.8GB/s. (small files are of course always slower).

    I've also tried other software options for file copy:  

    • Robocopy (with and without /J and /MT),
    • Xcopy (/J),
    • Teracopy
    • Extreme Copy
    • TotalCMD
    • CopyHandler
    • CopyItem in Powershell
    • CopyHere in WSH

    And all of them were as slow as File Explorer or slower.

    Until I tried yet another freeware filecopy tool called FastCopy and to my surprise the average copy speed climbed to 5.1GB/s

    FastCopy Details:

    5100MB/s sustained speed while copying two ~23GB mp4 files from one 1TB WD Black SN850 (connected to X570) to one 1TB WD Black SN850 connected to R9 5950X.

    4700MB/s sustained speed while copying same two ~23GB mp4 files from one 1TB WD Black SN850 (connected to R9 5950X) to one 1TB WD Black SN850 connected to X570.

    (so writing through the X570 chipset has a ~10% performance penalty (compared to directly connected to CPU).

    Still >2GB/s faster than File Explorer (at ~2.5GB/s avg)).

    Just give it a try. It's freeware. https://fastcopy.jp/

    Other tips:

    1.) Most TLC drives have dynamic write cache (i.e. the more free space the more write cache). So don't test with almost full drives.

    2.) After deleting much data (while testing), retrim the drives (Win+R -> dfrgui.exe) before testing again, to make sure the drive's available space is ready to be written (and no background maintenance is slowing down your drive).

    3.) Use large files and to see maximum speed (but writing data larger than the write cache will see a sharp drop in speed, this  will also happen with File Explorer).

    4.) FastCopy also supports  "Shell extensions" (you need to manually enable this in the settings), so you can paste with FastCopy by right clicking on a folder.

    BTW, I am not affiliated with FastCopy or its developer(s).

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  4. Anonymous
    2021-04-12T19:48:35+00:00

    I understand your logic, however the drives I am using are running (explicit in BIOS) at PCIe 4.0 x4 speeds, or 8GBytes/sec of maximum hardware throughput for a single connection.  Even if by some magical mishap the bios says PCIe 4.0 but it was still running at PCIe 3.0 x4, I would still expect 4GBytes/sec of maximum hardware throughput per connection, way more than I'm experiencing here.

    I do now believe through all of the data & facts I have given in my original post that there is a fundamental issue or bug in how Windows (current Pro version) handles file copying at the Explorer level and possibly more.  If this is the hypothesis here, is this not the correct forum where it is appropriate to investigate further ???

    Again, a hard limit of ~2GByte per second on NVMe file copy speeds when using a non-Intel platform motherboard and CPU combo.

    Whether or not they are software RAIDED.  This limit should not exist.

    Thanks again for all your help.

    I am still waiting on the hardware manufacturers replies as well.

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  5. Igor Leyko 111K Reputation points Independent Advisor
    2021-04-10T13:23:54+00:00

    Hi Olivier,

    My name is Igor, I'm Independent Advisor. It's a pleasure for me to help others and I'll do all my best to help you.

    There is no limits in Windows but may be limits in hardware - both from SSD and from CPU.

    Are your files defragmented? Fragmented files require much more calculations so this may decrease read-write speed. Please note, benchmark tools do not use file functions so may be significantly faster then normal operations.

    Sorry but in fact your question is hardware related so please ask a help from motherboard and SSD manufacturer's support.

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