New Sandisk Extreme(microSDXC) 256GB sd-card, had 32GB of unallocated space...why? Overprovision??

Hello, good people in here! :slight_smile:

I just bought this new 256GB Sandisk sd-card for my (also new)outdoor surveillance camera.
I first wanted to check if the card was working and reported the correct allocated space, so loaded up windows 10 and the diskmanagement tool, and then got really confused seing the sd-card was partioned to have 32GB of unallocated space.

As I didn’t expect this, but my knowledge on sd-card technology is also limited…I got curious and wanted to ask Sandisk/you guys- why it is, that they choose to partition their sd-cards this way? Is there a “overprovisioning” effect like seen on SSD disk’s, where it extend memory cells life?
Or is it perhaps more usercase based, wether it has a benefit or not? (in my case, I’m gonna use it in a network camera for continuous or motion based video recordings).

I did google it first, but only answer I got, was that overprovisioning didn’t work on sd-cards, as they didn’t have any memory controller technology like “TRIM”, to register the write calls to each memory cell and then make sure to redistribute the writes even among them all. If this is the ONLY answer, it makes no sense why Sandisk would do this…I choose to believe Sandisk has a reason! :wink:

Hope to learn something new! :slight_smile:

Hi @Sandisk_buyer,

Have you opened a Support Case? If not opened, for more information, please contact the SD Technical Support team for best assistance and troubleshooting:

Hello there!
I figured my question was a very “basic” and simple one, and therefore most appropriate to ask on a forum! :slight_smile: