DVD Burning Question - Can't get advertised amount

Discussion in 'macOS' started by mcmike100, Jul 24, 2006.

  1. mcmike100 macrumors member

    Jan 31, 2005
    I've found that Finder will never let me burn more than 4.4gb or so onto a DVD, even though the DVDs claim they can hold 4.7. Is this normal, because the DVD needs extra space to write info about the files or something?

  2. Eraserhead macrumors G4


    Nov 3, 2005
    It's another case of the 1000 bytes in a kilobyte for Hard Disk (and clearly other media) manufacturers and 1024 for OS's, basically a 4.7GB DVD should hold 4.38GB.
  3. brepublican macrumors 6502a


    Jul 22, 2005
    It's not just Finder, the same is true of DVD burning apps on Windows (at least with the newest version of Nero) and Toast Titanium on Mac. I think it has to do with the fact that 4.7GB is not actually 4.7 gigs. If you're using 1MB = 1000B then the 24B can really carry over and become quite significant. Another example is an iPod mini 4GB being able to only hold about 3.7Gb of data.

    EDIT: Quick fingers Eraserhead
  4. REDSRT4 macrumors regular

    Jul 20, 2006
    Yeah that is all i can burn as well! Sounds fine to me!
  5. balamw Moderator


    Staff Member

    Aug 16, 2005
    New England
    It's worse than that since each factor of 1000 needs to be replaced with 1024 so a decimal 1 GigaByte = 1 GB = 1000x1000x1000 while the binary version used by the OS is 1 Gibibyte = 1 GiB = 1024x1024x1024. You end up overestimating the binary sizes by 7.4 % using the decimal numbers supplied by the media vendors...

    I do wish the OS would ctually say GiB and not GB.

  6. Chundles macrumors G4


    Jul 4, 2005
    This is all early computer makers' fault

    They should never have used SI prefixes for units of binary storage.

    "Kilo" should only refer to a thousand of something, not 1024.
    "Mega" should only be used for a million of something, 1048576.

    This is where all the hassle began, the advertised space on your HDD, DVD etc is correct, 4.7GB = 4,700,000,000 bytes which is 4.7GB.

    Unfortunately your computer works with storage in units of 2, for it a "Gigabyte" is 2^30 bytes which is incorrect, 2^30 IS NOT a Gigabyte.

    The difference between what really is a Gigabyte (10^9) and what a computer calls a "Gigabyte" is about 7%.

    Have a look at this Wiki page to see why computers and manufacturers should be using Binary Prefix Standards instead of SI standards.

    Gigabyte? Not really...
  7. mcmike100 thread starter macrumors member

    Jan 31, 2005
    Thanks for the thorough explanations, everyone!
  8. tdhurst macrumors 68040


    Dec 27, 2003
    Portland, OR

    I REALLY wish there was some way to better educate more people about this question...it's asked ALL THE TIME.

    Stupid marketing people and their stupid math.
  9. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    I can kind of see how this got started, since the difference was pretty small way back when--the extra 24 bits on a kilobyte wasn't a big deal. When you get up into the gigs, you start noticing it a lot more, though, and when we start getting into terrabytes, it's going to be a full 10% off--that's just silly.

    If the OS vendors would just start putting GiB instead of GB, it would help, but they'd all have to start doing it to have any meaningful effect on the even moderately technically literate. Or they could just report atctual decimal GB and have everybody's files suddenly get larger, except again you've got literally decades of momentum behind the other system that's going to cause confusion.

    Maybe we need another one of those lawsuits to force drive manufacturers to report in GiB like when the monitor manufactuerers were forced to actually put viewable area on CRTs. Yes, they always put a little disclaimer to avoid it, but you'd think just to avoid tech support calls somebody would be pushing to change this.

    C'mon, Seagate, would it be so hard to say "500GB 7200.10 (465GiB OS capacity)" or something? It's no more confusing than saying "17" (16.1" vis) Monitor."
  10. tdhurst macrumors 68040


    Dec 27, 2003
    Portland, OR

    Then let's change it NOW instead of letting it get worse and worse...what happened to truth in advertising?

    In all honesty, we're not receiving what any REASONABLE person would expect they're buying...

    At least food companies go by weight and not capacity (some contents may settle when shipped) so they can actually say you're getting X ounces of something.

    Just a thought...

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