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Slow BR read FI_UNKNOWN and 0xc01c0004 RRS feed

  • Question

  • I am trying to copy data from a BR drive. The throughput is about 6MB/s. It should be 30MB/s.

    Xpref shows that errors are occuring. Every other line has

    2.899021082, 2.899044730, 23.648, 0xfffffa80055680e8, 0xfffffa8006cf1440, 524288, F:\data.rar, 5242880, Internal error code used by the filter manager to determine if a fastio operation should be forced down the IRP path. Mini-filters should never return this value.
    ,(0xc01c0004)

    and about every 5th line has

    2.907625442, 3.154774107, 247148.665, 0xfffffa80046f3dd8, 0xfffffa8006ec3d10, 4096, \FI_UNKNOWN, 2682880, nocache, paging_io synchronous_paging_io

    Success(0)

    which takes 250ms.

    everything else looks normal.

    Any ideas how to fix these problems and speed up the copy? On Win7 I can sustain 30MB/s+ without issue both read and write. Fresh install of win8 when tests were done.


    Tuesday, March 5, 2013 4:56 AM

All replies

  • 1. Update the latest driver manually.

    2. Disable security software and firewall temporarily.


    Niki Han
    TechNet Community Support

    Thursday, March 7, 2013 4:02 AM
  • It says driver is up to date. I disabled every non-critical service(audio, network, etc...) and it did not effect the speed.

    The problem seems to be with a bug in the driver. Whatever FI_UNKNOWN is, is causing the slowdown.

    The issue seems to be the driver trying a command that does not work on the drive. For large files the drive goes full speed(Several GB) but for a ton of small files the speed is reduced significantly(because of those bad commands interspersed between each file copy).

    Also, burning files goes full speed. Hence this must be an issue with windows 8.

    Thursday, March 7, 2013 4:47 AM