SD Card Reader problem

[NoSleep]

I bought a 256GB microSDXC, plugged it into my old SD card reader and tried to format it and it now says the card is only 15GB. I figured that maybe I need to get a more up-to-date card reader (that knows what SDXC is) but wondered if it will allow repair/recovery of the original capacity, or have I screwed that?

[Sonny_Jim]

Open up 'Disk Management' and have a look and see if it's just made a single 16GB partition.  Press the 'Windows' key and type 'disk management', you should have an option for 'Create and format disk partitions':



Have a look at the list of disks in the bottom pane, one of them should say 'Disk 2' (or whatever) and show how big Windows thinks the disk is.  If it's the correct capacity, use that app to delete and create a new partition that fills the disk.

sidenote: Make sure you are working on the correct disk by unplugging  the card reader and seeing which one disappears.  You really don't want to delete and format any other partitions because that would be extremely bad, Ray.

[NoSleep]

I'm going to have to wait until the new card reader turns up, as I think that is the source of the problem. Sticking another 128GB microSD in my current reader yielded that it was less than 20GB in size. It's just not recognising newer, larger SDs.

[touchingcloth]

Weird that 15GB (or probably 16GB really) would be the limit, given that SDHC has a limit of 32GB and normal SD of 2GB.

Do you have a different port or computer you could plug the same reader into as a quick test to see that that's not causing some weird issues?

[Memorex MP3]

Has the older card ever stored more than 20gb? They could be fake cards labeled as larger than their actual physical capacity (This is fairly prevalent, I gather)

[NoSleep]

Has the older card ever stored more than 20gb? They could be fake cards labeled as larger than their actual physical capacity (This is fairly prevalent, I gather)

The 256GB one is new and I believe it not to be a fake from watching this:

The 128GB one has been happily providing 128GB on my Switch for the last month, so I'm sure it's not a fake either.

[NoSleep]

Weird that 15GB (or probably 16GB really) would be the limit, given that SDHC has a limit of 32GB and normal SD of 2GB.

Do you have a different port or computer you could plug the same reader into as a quick test to see that that's not causing some weird issues?

The fact that it's showing odd capacities is weird enough for me. It's very old. I don't think I ever used it for anything larger than 8GB before now.

[Memorex MP3]

What's the sd card reader you're using?

[NoSleep]

A very old Integral one: "USB 2.0 HiSpeed Multi Card Reader/Writer"

Like I said, I need a new one (arriving tomorrow) and my original question was will a modern card reader allow repair/recovery of the full capacity, or have I screwed that?

[Sonny_Jim]

Old USB SD readers are known for just going bad, I did see a hackaday article about it where the conclusion was basically 'cheap timing crystals'. 

I've had Windows get all confused about card sizes before, in Linux I use a command to just write zero's across the MBR and that usually does the trick.  There is probably a Windows equivalent (the 'official' SD card formatter, maybe?)

[NoSleep]

I'm on Macs here if I need to do that. Hopefully the new card reader (apparently out for delivery) will see what's going on.

[first skeleton on mars]

can't think of any way the dodgy formatting would have permanently changed the card's storage capacity. not entirely convinced it was the card reader's fault (you'll find out soon I suppose) but reformatting it correctly should fix it yeah.

what did you format it with? Disk Utility?

[NoSleep]

what did you format it with? Disk Utility?

Yes.

[NoSleep]

Ha! I just happened upon another card reader I own, and that has correctly seen all 256GB on the offending SD card:



You can tell something went wrong via the other card reader, as I named the formatted part "SAMSUNG", not "Untitled".

[studpuppet]

Any SD card problems I've ever had have been solved by using the SD Association's official formatter:

https://www.sdcard.org/downloads/formatter/

[NoSleep]

Any SD card problems I've ever had have been solved by using the SD Association's official formatter:

https://www.sdcard.org/downloads/formatter/

Just tested this on my Mac. It was not able to do better about seeing 256GB instead of the wrong 15GB using the old SD card reader. It could see the 256GB with my new card reader, but the only options it gives are "quick format" and "overwrite format" rather than giving multiple options as to what type of format you require. In contrast Disk Utility gives me 12 different possibilities.

Do you know if the type of format it applies is FAT32/Master Boot Record, as nothing is specified? EDIT: Apparently it's some kind of universal formatting that's meant to be readable on different platforms. Unfortunately, I specifically require FAT32/MBR format.

[first skeleton on mars]

have you sorted it with the other card reader, or is it still giving you problems?

[NoSleep]

I have formatted it the way I require, so far as I know, but have yet to put it to use as I've been otherwise busy. Actually it's hard to tell if it's correct on a Mac, but I have Windows 8.1 installed on another HD for that Mac, which I'll use to check it when work quietens down. I think the options for formatting it correctly, if it isn't already, are going to be found there.