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Folder Size vs Disk Size

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brucine Posted messages 24865 Registration date   Status Member Last intervention   -

Hello,

I have a 1TB hard drive where I have stored hundreds of GB of files from 2 USB drives and a hard disk, but the total size of all the files on the 1TB drive is less than the space they occupy on the disk (size: 437GB, size on disk: 446GB).

Screenshot available upon request.

Thank you.

2 answers

  1.
    brucine Posted messages 24865 Registration date   Status Member Last intervention   4 172
     

    Hello as well,

    We find it hard to understand, 400 GB and some change does not formally represent "hundreds," but it doesn't matter.

    Each drive has a commercial nominal decimal format, for example, 500 GB, but will actually represent only 465 once installed and thus in binary.

    This illusory "loss" will be specific to each drive and the cumulative value of multiple drives will not necessarily equal the value of the combined data on a single drive.

    To make matters worse, depending on the format of the medium (FAT32, NTFS...), its size, the type of operating system, the default cluster size is different and means that the same volume of data will not fill the same space.

    Obviously, there are no other evaporative factors affecting the storage value of the data.

     

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  2. blux Posted messages 5032 Registration date   Status Moderator Last intervention   3 455
     

    Hello,

    it's normal, Windows stores its files in fixed-size disk space blocks (called 'allocation units', visible with the 'chkdsk' command).

    Most of the time, they are 4096 characters under NTFS.

    A file of 300 characters will take 4096 characters on the disk (one allocation unit).

    A file of 6000 characters will take 8192 characters on the disk (two allocation units).

    That's the difference you see.

    The fewer files you have on your disk, the less noticeable the overall difference will be.

    Catch you later blux "Fools will do anything.
    It's how we recognize them."

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    1. brucine Posted messages 24865 Registration date   Status Member Last intervention   4 172
       

      Hello,

      Yes, that's what I outlined by referring to "clusters" in proper French.

      The geometry of the disk is no longer relevant in principle, as the size of the physical sectors has become the same across all disks.

      On the other hand, to a certain extent we can choose the size of the logical sectors when formatting the disk, which depends by default on the operating system, the type of partition, and the size of the medium, and once done, it can be checked by less aggressive means than CHKDSK.

      A quack calculation aimed at optimizing this space doesn't make much sense since it would require prior knowledge of the size of all the files to be stored.

      https://www.malekal.com/secteur-cluster-unite-allocation-et-bloc-de-disque-quest-ce-que-cest/

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