[Crosseye_Jack]

afaik, thats so the device can format the card in its preferred filesystem. Instead of pestering the user (who may only use their computer as a "Facebook machine") to make sure they format the card to X specification, the device can just do that for them. Outside of "that", the device isn't doing anything special during format (unless its using the "secure" bits of a SD card, which pretty much no one does).

However, as at least some of the devices users will be Windows users, it does tend to limit the FS choices to FAT, exFAT or NTFS if the user expects to treat the card as removable storage to transfer files, like in a digital camera, so the issue is pretty much moot. Unless MS are still charging royalties on FAT and the device manufacturer wants to avoid those.

These days with people mainly using their phones, and the transfer of files being done over the air, allows device manufacturers more freedom with their SD card FS choice.

[bayindirh]

Most professional cameras still use ExFAT and AFAIK Microsoft doesn't charge inclusion of ExFAT drivers on these devices anymore.

However, sometimes devices format these cards in slightly specific ways they like (sector sizes, partition offsets and like) so the cards work well with the devices.

My Sony A7-III has an intelligent way of testing cards without reading/writing extensive data and reporting whether the card can handle particular video bitrates. I think SD cards have some tricks we still don't know as consumers much.

[Crosseye_Jack]

Sorry, yeah I prob dumbed it down too much by just saying the file system. But you are right that some devices will prefer a certain sector size, partition layout, etc, and while these can be done manually by the user outside of the device, its just "easier" for the vast majority of people if the device just does that for them.

Which IMO is where the whole "Its better to let the device format the card" came from. Because techs just got sick of trying to explain to less tech savvy users that "yes its possible to format the card in your computer, but just use the devices in built formatter handle it for you", because I know I told users that all the time back in the day, lol.