Increased filesizes

  • We are moving our current archive pacs server to new hardware.
    When transferring the files between our 2 servers I noticed they are increasing in size, approx 200%.
    Both servers are set up with exactly the same configuration.

    JPEG2000 support
    NKI compressed
    Saved as V2

    IncomingCompression = n4

    When speccing out the new server, we calculated in future growth, but no increase in moving the files.

    Is there anyone that can shed any light on why this might be happening and if this is preventable?


  • Dicom config can be found at the bottom.
    Going back to 1.4.16j is not an option. We had severe crashing issues with that version. Sometimes up to 5 times a day in each of our locations.
    This was fixed when upgrading to 1.4.16k

    I have no real attachment to the NKI format. This is just the format the systems were using when we took over the IT infrastructure.
    I started reading more about this in the last couple days and decided that a change to DCM files with jpg lossless compression will do as good a job if not better of saving space, with the added benefit of being compatible with more devices.
    I know about the speed difference, which shouldn't be an issue once the initial conversion is completed.

    When I was moving the 9TB of nki images to the new server, it was going to finish in 53 hours.
    It seems that moving the same amount to DCM and jpg compression will be over 200 hours.

    After reading this thread and testing myself I had a couple more questions:
    - If there is a bug in the NKI format since the latest version, does that mean all images created since then are larger than supposed to and will need to be recompressed later on to gain space?
    - Are there any other considerations in choosing between V2/NKI and DCM/jpg except for compression speed and compatibility?

    If one or the other is clearly better I have the ability to switch some servers and storage around to convert all of them to the same format. (for now, that none of the locations has more than 10TB yet)

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