Do blu-ray discs hold data longer than DVD discs?

Discussion in 'Amateur Video Production' started by Brian, Feb 27, 2012.

  1. Brian

    Brian Guest

    I'd be interested to know if the data on a Blu-ray discs are better at
    storing data than DVD discs. I've read about data loses on DVD's and wonder
    if it also applies to Blu-ray discs. Are Blu-Ray discs more reliable?

    I've read that there is less chance of scratches due to the protected layer
    added to the blu-ray disc.
     
    Brian, Feb 27, 2012
    #1
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  2. We know even less about Blu-Ray than we do about DVD; what we do know
    comes from accelerated aging studies, which always involve considerable
    undertainty. By the time we've had Blu-Ray disks long enough to know if
    they last 100 years or not, nobody will be making new blanks any more
    :).

    Given the much higher data density (meaning much smaller spots of dye
    representing each bit), I certainly would not bet on longer life. If
    we're lucky, they've improved the dyes and the protective coatings and
    the error correction codes enough that we haven't *lost* any archival
    live, but hoping for an actual improvement seems rather optimistic to
    me.

    Also, I use MAM gold archival DVDs; last I loooked nobody was making
    anything at that quality level in Blu-Ray yet.
     
    David Dyer-Bennet, Feb 27, 2012
    #2
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  3. Brian

    Mxsmanic Guest

    I think it depends much more on the specific recording technology used than on
    whether it's DVD or Blu-ray.

    The lifetime of recorded CDs (CD-R, CD-RW) still has not been accurately
    determined, since the vast majority of them are still readable. The lifetime
    of mass-produced CDs is presumably much longer, but all of those are still
    readable, too.
     
    Mxsmanic, Feb 27, 2012
    #3
  4. Brian

    Brian Guest

    Thanks David and Mxsmanic for your replies.
    Looking on the bright side I have not heard of anyone getting errors after
    recording to Blu-ray disc. I have hired some Blu-Ray movies and have not
    found any scratches on the surface compared to DVD's that I have hired in
    the pass so maybe the protective layer gives more protection.

    I read that its easier to manufacter a Blu-ray disc and manufactors are
    hoping that people will switch to Blu-ray does so I don't understand why
    its more expensive to buy a blank Blu-ray disc.

    I have a feeling that in the near future we will be storing what was
    recorded from the camera on the internet. As soon as it is recorded in the
    camera it will be sent to the internet in a secure place.
    YouTube and iCloud are starting to make that possible.

    My local library has said that they will looking at a way where people can
    download a movie to watch rather than borrow a DVD movie.

    Regards Brian
     
    Brian, Feb 28, 2012
    #4
  5. Brian

    Mark Guest

    I've come across loads of CDR/RW/DVD?R/RWs that can't be read after a
    short time.
    I don't recall any problems with manufactured CDs but I often get
    rental DVDs that won't play.
     
    Mark, Feb 28, 2012
    #5
  6. Brian

    Mxsmanic Guest

    Why? That's like faxing a copy of a book each time someone wants to read it,
    instead of just keeping a copy of the book on the shelf.
     
    Mxsmanic, Feb 28, 2012
    #6
  7. Brian

    Mxsmanic Guest

    I've experienced one unreadable CD-R. I don't use RW variants.
     
    Mxsmanic, Feb 28, 2012
    #7
  8. Saves the time and energy (including gasoline use) of traveling to the
    library.

    Also reduces the cost of having 24 copies of the newest books (they're
    loaning ebooks, too) somewhat (depending on the details of how the
    publishers and authors get paid).
     
    David Dyer-Bennet, Feb 28, 2012
    #8
  9. Brian

    HerHusband Guest

    I'd be interested to know if the data on a Blu-ray discs are better at
    I have not used recordable Blu-Ray discs, but have had many bad
    experiences with recordable CD's losing data. Commercial DVD's are
    pressed and should theoretically never wear out, but recordable discs
    rely on organic dyes that can degrade over time. Factoring in the risk
    of degradation, the slow read/write times, and the limited storage space,
    optical discs just aren't a reliable backup media for me. They're fine
    for viewing your movies, or sharing video with friends and family, but I
    would never rely on them for archiving.

    I personally use external USB hard drive's to perform backups. For me it
    is about redundancy. I store my video's on the hard drive of my
    computer, then back up nightly to an external USB hard drive. Once a
    month or so, I swap my backup drive with a second USB drive I keep in a
    safe deposit box at the bank. This gives me three copies of my files, so
    "WHEN" any of the three drives fail, I still have two other copies I can
    recover the files from.

    Even if you had a recordable media (CD, DVD, Bluray, etc.) that was 100%
    reliable for the next 1000 years, you still have to think about fires,
    floods, thefts, warping, or simple physical breakage. Not to mention you
    would need a device to play that media 1000 years from now.

    Hard drives are inexpensive, reliable, and have the lowest cost per
    megabyte. I bought 1TB, 2.5" external drives for less than $100 each.
    The small size fits easily in my safe deposit box, whereas a CD or Bluray
    disc would not.

    To be fair, there are two weaknesses of hard drives:

    1. The drive can be damaged if you drop it, though most drives these days
    are fairly rugged. Accidents happen, but in the last 10 years I have
    never dropped a drive or damaged it physically. Still, I "expect" the
    drive to fail, which is why I keep multiple copies of my data. It would
    be a bummer to drop a drive and damage it, but I could always get a new
    drive and backup my data again using the other copies.

    2. Hard drives are rewriteable, which means the data on them can be
    altered unknowingly by a virus or other cause. I have never encountered
    this situation, but I still create MD5 checksums using software such as
    ExactFile so I can verify the contents are unaltered from time to time.

    Anthony
     
    HerHusband, Feb 28, 2012
    #9
  10. Brian

    Mxsmanic Guest

    So it's essentially free movie downloads ... I don't think copyright holders
    will be too happy about that. One of the reasons libraries are allowed to loan
    copies of copyrighted material is that the library retains ownership of the
    material and borrowers cannot keep it indefinitely.
     
    Mxsmanic, Feb 28, 2012
    #10
  11. Brian

    Gavino Guest

    But what is a 'secure' place?
    I expect many people who saved stuff on MegaUpload thought it was secure.
     
    Gavino, Feb 28, 2012
    #11
  12. Brian

    Mike S. Guest

    There's always M-DISC (a DVD+R using inoganic substrate) from Milleniata.

    A bit pricey, and only specific LG burners will write to them, but even
    if they last a fraction of the rated 1000 years, your recordings will
    probably outlast the DVD format itself.
     
    Mike S., Feb 28, 2012
    #12
  13. You clipped the part where I mentioned that very issue, and implied that
    something was being done with it. Why?
     
    David Dyer-Bennet, Feb 28, 2012
    #13
  14. Brian

    Brian Guest

    Anything plugged onto the usb outlet of a computer is slow to transfer
    data. Blu-ray discs are very fast at transferring data.
     
    Brian, Feb 29, 2012
    #14
  15. Brian

    Brian Guest

    You would not own the movie as it would expire after the loan period. The
    only problem is that you might have to watch the movie on your computer or
    attach your computer to your TV.
     
    Brian, Feb 29, 2012
    #15
  16. Brian

    Brian Guest

    Good plan but it would cost me money to keep my hard drive at the bank.
    Maybe that's why people are looking into backing up media by uploading it
    to the internet (eg iCloud).
    What about earthquakes and other disasters. You need to keep your backup in
    a different location (eg internet unless you do a lot of traveling.

    But if something goes wrong 1 Tb is a lot of data to lose. Hard drives wear
    out also. I would loan someone a dvd but not a hard drive.

    During an earthquake my hard drive fell off the table but still worked.
    Disconnect from the internet when backing up on a hard drive.
     
    Brian, Feb 29, 2012
    #16
  17. Brian

    Mxsmanic Guest

    Cloud computing really isn't practical unless and until you get really fast
    networks, and we are lightyears from that right now. Cloud computing is also
    extremely insecure, and I certainly wouldn't trust it for back-ups.
    Yes ... although simple disk failure (or other hardware/software problems) are
    much more of a risk than natural disasters.

    I'm reminded of the French bank that lost mountains of data because it took
    back-ups of the servers every night ... but left the back-up tapes on the
    drives after the back-ups. So when a fire consumed the computers, the back-ups
    were lost as well. (There are rumors of hanky-panky in that particular case,
    though.)
    Everything mechanical seems to be getting sturdier, which is a good thing.

    And here I'm reminded of the Sony salesperson who demonstrated the sturdiness
    of Betacam SP broadcast camcorders by simply dropping them onto the floor,
    picking them up, and continuing to work. Sony equipment has always been very
    sturdy even at consumer levels.
     
    Mxsmanic, Feb 29, 2012
    #17
  18. Brian

    Mark Guest

    I disagree.
    I dropped two Sony consumer camcorders a short distance onto the
    ground. An old Hi8 camcorder was undamaged except for a scratch. A
    newer MiniDV was smashed to bits.
     
    Mark, Mar 1, 2012
    #18
  19. Brian

    HerHusband Guest

    Brian,
    Blu-Ray's are rated at 36 Mbps at 1X speed, or 72 Mbps at 2X speed.

    USB 2.0 is rated at 480 Mbps.

    While real world speeds usually don't meet the specs, USB 2.0 drives
    easily outpace Blu-Ray disks.

    (USB 1.0 was only around 15 Mbps or so, which would indeed be slower, but
    most computers these days have 2.0, with 3.0 becoming more popular.)
    We have the safe deposit box anyway to keep our passports, and old photo
    negatives safe. So, there's no additional charge to stick the backup
    drive in there too.

    In any case, we only pay $30 a year for the smallest 3"x5" box (I think
    it's about 16" long). A small price to pay for safe storage.

    If you can't afford a safe deposit box, you could still store a drive at
    a friends or family members house, in your desk at work, or even in your
    car. You would probably want to encrypt your backups though if you keep
    them a public location like that.
    Uploading anything to the internet is SLOW! It can be handy for backing
    up files you want to access from multiple locations (music files, videos,
    documents, etc.), but it's not realistic for full system backups.

    What happens if you have a complete system failure? How will you retrieve
    your files from the internet to restore your computer? What if your
    internet connection goes down? What if the server is down?
    My safe deposit box is in town, about 10 miles from my house. It is
    unlikely most natural disasters would affect both locations. Even if it
    did, the safe deposit box is in a bank vault after all. :)
    All backup media WILL fail at some point. Trust me, I've used most of the
    options over the years and have had failures with every one of them.

    That's why it is important to keep multiple backups of your data. When
    one fails, you still have the others to recover from.

    Also, you have to factor in the labor involved in backing up. My hard
    drive backups are performed automatically every night. I don't need to
    put a disk in the drive or open any burning software to perform the
    backup. If your system crashes and you haven't backed up in weeks, you
    lose everything since your last backup.

    Granted, a connected backup can be taken out with the main drive in the
    case of a power surge, virus, etc. But you are more likely to delete
    files by accident than a system wide failure. Even when that occurs, you
    have the other non-connected backups to fall back on.
    That's a different situation. I wouldn't loan out my hard drive either.
    I burn DVD's when I want to share a video or something with family.

    If I was sharing "data" with another computer user, I would be more
    likely to use a USB flash drive. They're smaller, faster, and easier to
    write to. And they are reusable.
    My computer is on and connected 24/7/365. Disconnecting wouldn't prevent
    viruses, power surges, hardware failures, etc. anyway.

    Anthony
     
    HerHusband, Mar 1, 2012
    #19
  20. You're forgetting to account for the mile-wide asteroid :)
     
    Gene E. Bloch, Mar 1, 2012
    #20
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