Weird CF card problem: 4GB Sandisk Ultra II cards formatting as only 2GB

Discussion in 'Digital Photography' started by Lionel, Apr 22, 2006.

  1. Lionel

    Lionel Guest

    Per the subject line, I have a pair of Sandisk Ultra II 4GB CF cards
    that have started showing up in Win Xp, Linux & on my EOS 1Dmk2 as
    having a capacity of only 2GB instead of the full 4GB. Formatting them
    on any of the above systems makes no difference. I've also tried
    zeroing out (dd command in Linux) the first couple of MB on one card
    in the hope that it'd scrub any spurious disk signatures that might've
    been placed on the card by 'doze, but it made no difference.

    Any ideas on what might be the matter, & how I can fix it?
    Lionel, Apr 22, 2006
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  2. Lionel

    Paul Rubin Guest

    You formatted as fat32, right?
    Paul Rubin, Apr 22, 2006
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  3. Lionel

    Lionel Guest

    It turns out that the 4GB cards have a tiny switch on the side that
    can limit the capacity to only 2GB for compatibility reasons:
    I have no idea how it happened, but my card was set to the 2GB
    compatibility mode. Switching it to full capacity has fixed the
    Lionel, Apr 22, 2006
  4. Lionel

    Lionel Guest

    Yep. The problem turned out to be a configuration switch on on the
    card itself. Like an idiot, I posted my question here before checking
    the Sandisk FAQ for this particular model of CF card. OTOH, I think I
    can be forgiven for failing to notice a microscopic black plastic
    switch tucked into the bottom of the black plastic guide slot on the
    side of the card itself. ;)
    Lionel, Apr 22, 2006
  5. Lionel

    SleeperMan Guest

    although i really don't see why would anyone buy 4G card and then use it
    only 2G...and thus throwing away quite a money...
    SleeperMan, Apr 22, 2006
  6. Lionel

    Bill Hilton Guest

    It turns out that the 4GB cards have a tiny switch on the side
    I *think* it formats as two 2 GB cards instead of one 4 GB card when
    you set the switch because of addressing problems with some older
    cameras ... so you don't actually lose half the disk space, you just
    have to acesss it awkwardly ... as least I think that's how it works
    .... I have one of these 4 GB cards but all my cameras work fine with it
    as one 4 GB space, except write speeds really slow down once you reach
    about 3 GB or so, so I haven't actually tested this theory ...

    Bill Hilton, Apr 22, 2006
  7. Lionel

    SleeperMan Guest

    hm...could be. But, in that case i wonder how a person selects first or
    second partition...
    anyway, for now i don't have similar problems, since 1G is quite enough for
    now. :)
    SleeperMan, Apr 23, 2006
  8. Lionel

    Lionel Guest

    I was wondering the same thing, but it turned out that the swicth has
    three positions: (1) 4GB, (2) 2GB, partition 1, (3) 2GB, partition 2.
    So if your camera doesn't support FAT32, you switch the card to the
    first 2GB partition, & when it's full, you take it out & switch it to
    the 2nd 2GB partition.
    Lionel, Apr 23, 2006
  9. Lionel

    Bill Hilton Guest

    I *think* it formats as two 2 GB cards instead of one 4 GB card
    Wow, that sounds so convenient I can't believe I've just left mine on
    the 4 GB setting :)
    Bill Hilton, Apr 23, 2006
  10. Lionel

    Gary Edstrom Guest

    The problem is that many cameras only support the FAT16 file system.
    That, by its nature, limits the total amount of addressable space to
    2GB, no matter how big a chip you have. To address more, your camera
    needs to be able to support the FAT32 file system, OR the memory chip
    needs to to split it up into multiple partitions.

    Gary Edstrom, Apr 23, 2006
  11. Lionel

    SleeperMan Guest

    that's great. In that case, it's all logical. And convenient, too.
    SleeperMan, Apr 23, 2006
  12. Lionel

    Dave Cohen Guest

    Did not the card come with some sort of instruction sheet or other
    Dave Cohen
    Dave Cohen, Apr 23, 2006
  13. Lionel

    Gary Edstrom Guest

    Who reads the instructions anyway? :)
    Gary Edstrom, Apr 23, 2006
  14. Mine didn't.
    And it failed today anyway in my 1D Mark II.
    It's my second ultra II card failure in less
    than a year (out of ~20 cards, 40 gigabytes).

    Roger N. Clark (change username to rnclark), Apr 24, 2006
  15. Lionel

    Lionel Guest

    Indeed. ;)

    In fact, I generally /do/ read the instructions, but I bought the CF
    cards as the same time that I bought my 1Dmk2, so I bet everyone can
    guess which manual got priority. ;)
    Lionel, Apr 24, 2006
  16. Lionel

    Lionel Guest

    Ouch. You've got me worried now, as I also shoot with a 1Dmk2.
    What kind of failure?

    PS: You might also want to check the FAT16/32 mode switch on your 4GB
    card, as it might be in the wrong position. Look for the little
    circle/half-circle symbols on the cards reverse label. The switch is
    in the slot on the nearest edge to those symbols.
    Lionel, Apr 24, 2006
  17. Lionel

    Paul J Gans Guest

    That's too many failures. Have you contacted the manufacturer?
    I'd be curious as to their reaction.

    ---- Paul J. Gans
    Paul J Gans, Apr 25, 2006
  18. I formatted the card in the camera, then started shooting. I shot about
    12-15 frames, when the card reported full. I can't write to it any more.

    My last card failed in a similar way.

    I am aware of the switch and had some dialog with sandisk about the switch
    and what effect it would have on data. This was when I first got the
    card about a year ago. After responding to several questions,
    I asked what would happen to the data if I accidentally moved the
    switch from the 4 GB position to one of the 2 GB positions.
    They would not respond after that.

    I have about 20 cards comprising 44 GBytes. Most are lexar cards,
    and my oldest are 512 MB sandisk cards, which have not given
    any problems. I have 3 sandisk ultra II cards: two 2 GB and one
    4 GB. Now one 2 GB and the 4 GB have failed. 2 out of 3 cards
    in a little over one year is too much for me.

    The first card failed in both 10D and 1D Mark II cameras,
    both on current firmware. I haven't yet checked the 4 GB
    in the 10D, but why bother: a failure means I would never trust
    the card.

    Both failures were in pleasant conditions: low 60s F, clear
    skies, no moisture.

    Roger N. Clark (change username to rnclark), Apr 27, 2006
  19. Not yet. I'll do that soon and report what I find.

    Roger N. Clark (change username to rnclark), Apr 27, 2006
  20. Lionel

    SleeperMan Guest

    just you by any chance take out card, put it in reader and
    transfer shots to PC? I was told that taking card out often may result in
    failure, but this was told for new Extreme III card...
    SleeperMan, Apr 27, 2006
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