[Stratoscope]

Was it an actual hard limit, or just something listed in a datasheet?

Device manufacturers will sometimes list a lower limit than what the device could actually support, simply because there were no larger capacity drives/memory available for testing at the time of release.

I've seen this a few times with ThinkPads, not sure about phones.

[est31]

Capacity limits for drives exist because the maximum capacity of SD cards depends on the protocol used: SD, SDHC, SDXC, SDUC. Each protocol requires driver support in the device. Hardware wise, there isn't many changes required though, and to some degree this partitioning is also artificial because one can just make a standard that supports horribly gigantic capacities.

But anyways, the limit exists, and this means that whether your device can support larger SD cards after it is released depends on whether the driver is getting updates or not. Android phones are quite known for not releasing driver updates, although often there is updates for Android phones as well. Thinkpads are IBM computers, and the update story is way better there.

[Shawnj2]

In most cases I’ve never actually run into this as an issue. For example the 3DS only officially supports SDHC cards so up to 32GB of data but if you format a larger card as FAT32 it works perfectly fine.

[colinsane]

using a 256GB SD card on a phone that only advertises 32GB capacity right now... works fine.

but phones that advertise low capacity limits are probably also not wiring the SD interface for high bandwidth. it's not unusual to see internal flash capable of 100MB/s but SD interface only capable of 10MB/s :(