Topic: Micro SDXC 64 gig cards

[ts]

Out of four I have one that won't format. It worked great for about 3 months. I got tired of what was on it and decided to format and reload. I was only able to get 32 gigs on the reload. Tried GUI and SD formatter and no way is this 64 gig card taking more than 32 gigs. It's formatted to FAT32 per device specs (FII0). Every time I format it that 32 gigs is still there and the card won't take anymore gigs.To top it all off, this morning no machine will even read it. Dead! It's a Silicon Power Micro SD used with a new card reader capable of handling SDXC on Windows 7 machines. Without even being able to open it, I guess it's toast? My other cards are Sandisk and I've had no problems with them.

Edit: At one point I did toss it in an XP machine. I wonder if that tricked it into to thinking it was only a 32 gig card. I read something about XP not being able to read 64gb micro SD cards. Still doesn't explain why it is now dead.

[Gene Poole]

I got a counterfeit card from ebay once.  It said it was 64GiB, but writing anything past 32GiB resulted in file corruption.  Likely it was a 32 GiB card with allocation mapped twice to look like 64GiB.  Writing past 32G was probably remapped to the beginning and overwriting the existing files.  A PayPal dispute got me my money back.

This doesn't sound like your issue though.  More likely, your card has been partitioned.  An advanced disk management tool should be able to make a single partition, then it can be reformatted.  I don't know of a Windows tool for this; I'd use gparted for linux since I don't do windows if I can help it.

[ts]

My card is completely dead. Just trying to figure out what happened. Also trying to get a replacement form the company.