1 Gb?

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  • 01-19-2005, 12:22 PM
    mlang26
    1 Gb?
    Hi I just purchased a 1GB SanDisk Ultra II SD card for my Canon Digital Elph sd300. I've insterted the card and formatted it. The camera says the disk is only exactly 968 MB? It says 16kb is being used obviously because the card must be named, but do any of you know why its only showing up as 968 MB?

    Thanks for the help.

    Sincerely,

    Newb.
  • 01-19-2005, 12:42 PM
    Sebastian
    Re: 1 Gb?
    File system overhead. Same reason a 512 meg card will show 488 megs available, and every other storage medium out there also show less that total storage. Naming a card takes up almost no space, the 16k is beiung used by folders and other files the camera uses on the card.
  • 01-19-2005, 02:21 PM
    mlang26
    Re: 1 Gb?
    Thx for the help Sebastien.

    Its strange though. If a 512 stick uses only 488 (24 megs lost of system overhead) , then a 1024 should use only have 1000 left over. You might have to double the size of overhead given that a gig is double 512. So then on a 1024 meg card, you should have 976 left over. Yet for som reason I have only 968. So there is still 8 megs I'm missing somewhere. It's not very important to have that extra few megs, but Im just curious why they are missing. Maybe it depends on the carmera you are using?

    Not sure.

    Thanks again for your help Sebastien.
  • 01-19-2005, 02:50 PM
    Sebastian
    Re: 1 Gb?
    No, it's not at all that simple. It differs based on file system, and the amount does not scale in a linear way.
  • 01-19-2005, 03:19 PM
    mlang26
    Re: 1 Gb?
    Ok, Thanks for your help Sebastien, that's awesome, have a great day.
    :)
  • 01-20-2005, 06:19 AM
    Erik Stiegler
    Re: 1 Gb?
    There are two different megabytes. A camera or computer thinks a megabyte is 2^20 bytes (1,048,576 bytes, which is correct). Marketing departments call a megabyte 1,000,000 bytes. The difference is where most of the difference in the advertized size of the card and the useable space comes from.