I just bought a new sdcard. Before leaving the shop I ran a test. The test failed at 19GB. I tried to return it, met a lot of resistance and finally agreed that if they can show me it storing more than 30GB I'd accept it.

They managed to do that overnight. I felt silly and took the card. I ran a test again today and these are the results:

Data OK: 94.47 GB (198125585 sectors) Data LOST: 98.95 MB (202656 sectors) Corrupted: 98.95 MB (202655 sectors) Slightly changed: 512.00 Byte (1 sectors) Overwritten: 0.00 Byte (0 sectors) Average reading speed: 6.73 MB/s

I've accepted the card and I don't want to go back to that infernal shop. That's not my question.

My question is: What do I do next?

In my experience WITH HARD DRIVES, doing a bad block scan doesn't contain the error for long so what I would do instead is to partition around the problem. What are your thoughts on that?

  • This is a tech support question that doesn't really anything to do with photography, per se. Consider contacting the card manufacturer for a warranty replacement.
    – xiota
    Sep 26, 2020 at 5:37
  • 4
    I’m voting to close this question because it's much more a hardware question than a photography one.
    – Philip Kendall
    Sep 26, 2020 at 11:06

2 Answers 2


That's an entire .1% of the flash card that is returning bad data. Unless it's a bug in your flash card reader (which, BTW, is a very real possibility), I'd probably throw the flash card in the trash. (If it appears to be from a reputable manufacturer, it's probably a fake.)

I mean, a 128 GB flash card is only what, about twenty bucks? It's just not worth trying to use it and worrying about how many of your photos won't be there just to save $20.

There's no possibility of partitioning it to work around the problem. Flash drives reuse pages arbitrarily. If a flash page is reading back garbage data and the flash controller inside the card is failing to recognize that those pages are defective, then at some point, the wear count on some working cell is going to get too high, and it is going to copy the data from the bad page into a different page, then copy the data from the working page into the bad page, and you're going to lose data.

So the question should not be whether you can usefully use the flash card, but rather whether you should recycle it or send it to the landfill, which is more a question for your garbage hauler.

That said, before you throw it out, do repeat the test using your camera as a flash card reader. I've seen major data corruption problems with some cheap USB flash card readers over the years that were not the fault of the card. Also, check with the manufacturer (assuming the manufacturer isn't some fly-by-night vendor) about a replacement, just in case it is real.

I mean, if you desperately need an emergency fix to get you through the week, then maybe, maybe write some files across the bad blocks, and every time you take a picture, go back and hit play to make sure it is really there, but I really wouldn't trust that card at all.

  • 1
    It's a new card. OP should send for a warranty replacement, not throw it in the trash. Also, don't purchase from that store anymore.
    – xiota
    Sep 26, 2020 at 5:28
  • 1
    My strong suspicion is that if the card was fake. Otherwise, the store would have just swapped it, and the manufacturer would have handled the return. The only plausible reason not to swap the card for a new one is if they knew that they were scamming the O.P., and that all of their cards would fail like that.
    – dgatwood
    Sep 26, 2020 at 20:33
  • 1
    I suspect a fake too, and would agree with throwing it away if that's the case. The way your answer is written though, it seems you're recommending trashing the card even if it is not fake. If OP requests a replacement, the manufacturer will determine whether it is fake.
    – xiota
    Sep 27, 2020 at 1:59
  • Edited. That said, depending on how big the card is, the insured shipping might cost more than the card is worth. :-)
    – dgatwood
    Sep 28, 2020 at 4:46

Get the h2testw program and let it check the card as genuinely offering the given capacity. 98GB is a rather weird capacity in my book and (at best) points to an 128GiB card with an unusually large portion allotted as bad/reserve sectors. Or to a 64GiB card with tri-level cells (those are quite less reliable for data retention: I wasn't aware they were used for SDcards yet, though, so that may be completely off the wall. Just matches the unusual size and symptoms).

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