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How long before you can tell if an SD card is fake?

P

Paul7876

Well-Known Member
Hi,

A couple of days ago I received my new SanDisk 64gb sd card.

I've put it into my computer, fully formatted it, put several gigs of stuff on there, then ran a test on the remaining space and everything came back ok.

Now, my GS3 is telling me the card is damaged. Half an hour ago I was watching a movie on the card. Everything started going wrong when I triggered the media scanner.

How long do you have to wait before you can tell if a card is dodgy? Thanks :)
 
Download h2testw.exe for windows to test the card after a fresh format. Let it finish the test. Could take a few hours
 
Weird the edit above didn't show in tapatalk until I posted it.

Anyway +1 for h2testw I guess
 
Card was bought from a local retailer who I've found to be good in the past.

I remember having problems once before when I formatted a card on my computer instead of in the phone, even though I used the correct settings.

I've reformatted the card in the phone and so far it's ok, but I'll try the tests tonight when I get home.
 
I formatted the card and ran h2testw, with the option for all available space.
h2testw advised it was testing 60,901MB out of 60,902MB available space.
When the test finished, it reported no problems with a read speed around 17MB/s and a write speed of 11MB/s.
This problem seems intermittent, and will only occur when I've re-booted my phone.
Can anyone suggest any other solutions? I don't want to return the card and go back to 32GB and have to find another card (which will probably be more expensive :) ) unless I have to.
 
So far I haven't run the test straight after the error, I've only run it on a freshly formatted, empty card.

Whenever the error occurs, my phone refuses to mount the card until I've put it in my computer, formatted it then replaced the contents.

If it happens again (hopefully not!), I'll run the test straight after.

It's the intermittent factor and the fact it will only occur after a reboot (and not every reboot) thats making me wonder whats happening.
 
Sounds like an unclean dismount of the sdcard file system. If that's the case, it may be an incompatability issue with the device. Or app/data/settings issue causing your phone to act badly
 
Fakes are usually quite easy to find, using the tools already posted. Also if you try and store say 32GB of data, but find it can't read it back, you've got a dud. Often they'll appear to quick-format OK, because they lie to the OS.

Where I am, fakes are everywhere, espcially Sony, Kingston and Sandisk, so I usually only buy SD-cards and USB pen-drives from the local authorised Lenovo dealer, whom I can trust.

I wonder if Paul's problem is because he's trying to use a 64GB SD-card and perhaps the SG3 can't deal with that properly? OK with 32GB.
 
I've noticed some files seem to be stored as 0kb and I have trouble deleting these files. Having said that I've run two tests which have filled up the card and said it's ok.

I'm now wondering if something is messing up the FAT?
 
Ok, one final question - Is the Samsung Galaxy S III compatible with the SanDisk MicroSDXC UHS-1 Class 10 64GB? From what I've found, it is.

I don't believe the phone is at fault because I have no trouble with a 32GB card, and the 'damaged card' message only appears when I reboot the phone. Having said that, I sometimes see 0B files in file explorers which can't be deleted. After I refresh the list, the files show the correct sizes and can be deleted.

I'm also not sure the card is at fault, because even after the phone reports the card is damaged, I'm able to put the card in my computer and copy around 46GB of data off it.

This is my final push :-) Any thoughts or opinions before I go for a factory reset?
 
Solved!

I'm not sure why I didn't find this on my first round of searching, but I've come across a solution. I tried it a couple of days ago and everythings still fine so I thought I'd share.

It's to do with some bug in either Android or the GS3, but the solution is to format the card as FAT32. I've had no problems since doing this.

If anyone does need to format a 64gb card in FAT32, there's plenty of programs for this as Windows won't allow it. I downloaded a small command line program called 'fat32formatter' (or something like that).
 
Errr what now? I'd have told you that in my first post had I realised you weren't formatting fat32 :(

What were you doing?
 
Hi SURoot,

Sorry, I was formatting the card in both my computer and my phone, and exFat was the default option that was being used for both.

I didn't occur to me to change this at first as I assumed the default option would be ok.

Thanks again for your help :)
 
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