Windows 8 Pro 64-bit Optimization always leaves 18% fragmented RRS feed

  • General discussion

  • Hi, I have 524GB free of 698GB hard drive (HDD) and I noticed lately that Windows Optimization, when run, always finishes with 18% fragmented.

    I ran full maintenance tasks.

    I ran chkdsk /spotfix.

    I'm not sure what else to try.  Does anyone have any ideas?

    ps. spell-check doesn't work in the title area when you post something; It does work in the body.

    • Edited by Danny2000 Tuesday, February 19, 2013 2:01 AM
    Tuesday, February 19, 2013 1:57 AM

All replies

  • this is by design:

    In Windows XP, any file that is split into more than one piece is considered fragmented. Not so in Windows Vista if the fragments are large enough – the defragmentation algorithm was changed (from Windows XP) to ignore pieces of a file that are larger than 64MB. As a result, defrag in XP and defrag in Vista will report different amounts of fragmentation on a volume. So, which one is correct? Well, before the question can be answered we must understand why defrag in Vista was changed. In Vista, we analyzed the impact of defragmentation and determined that the most significant performance gains from defrag are when pieces of files are combined into sufficiently large chunks such that the impact of disk-seek latency is not significant relative to the latency associated with sequentially reading the file. This means that there is a point after which combining fragmented pieces of files has no discernible benefit. In fact, there are actually negative consequences of doing so. For example, for defrag to combine fragments that are 64MB or larger requires significant amounts of disk I/O, which is against the principle of minimizing I/O that we discussed earlier (since it decreases total available disk bandwidth for user initiated I/O), and puts more pressure on the system to find large, contiguous blocks of free space. Here is a scenario where a certainly amount of fragmentation of data is just fine – doing nothing to decrease this fragmentation turns out to be the right answer! kips fiels which are over 64MB.


    "A programmer is just a tool which converts caffeine into code"

    Tuesday, February 19, 2013 5:13 AM
  • Microsoft Windows [Version 6.2.9200]
    (c) 2012 Microsoft Corporation. All rights reserved.

    C:\WINDOWS\system32>defrag c: -A
    Microsoft Drive Optimizer
    Copyright (c) 2012 Microsoft Corp.

    Invoking analysis on (C:)...

    The operation completed successfully.

    Post Defragmentation Report:

            Volume Information:
                    Volume size                 = 698.49 GB
                    Free space                  = 521.93 GB
                    Total fragmented space      = 18%
                    Largest free space size     = 263.52 GB

            Note: File fragments larger than 64MB are not included in the fragmentat
    ion statistics.

            It is recommended that you defragment this volume.


    • Edited by Danny2000 Tuesday, February 19, 2013 7:13 PM
    Tuesday, February 19, 2013 7:12 PM
  • Considering investing in a high-performance, full-featured defrag program such as PerfeckDisk.  You can use it free for thirty days.

    Carey Frisch

    Wednesday, February 20, 2013 4:01 AM
  • Over the course of time since I wrote this, it is now down to 4% by doing nothing to resolve this.  My guess is that it does some of this (defragging) on some files as it is booting up and it might take a good number of reboots to fully get it to 0% on some installations depending on which files are fragmented.  That's just my guess.  Forcing it to "Optimize disks" didn't do a thing..and it has always been set to auto optimize at 3am and the computer is usually on at that time also.  So that's why I presume it is happening (defragmenting certain files) at boot-up.
    Saturday, March 9, 2013 3:12 AM
  • Also remember that it can't defrag files that are locked/in use.

    Another defragging app to try is Defraggler, although the only way you're ever going to get perfect defragmentation is taking the disk out of your current computer, putting it in another one as a secondary disk and running defrag from there. Honestly, unless you are seeing serious performance issues that you are absolutely sure are caused by fragmentation, I would leave the disk to Windows' normal optimizations. And if you're using a solid state drive, you shouldn't be defragging the disk manually at all!

    Monday, March 11, 2013 7:34 PM