Format SD Card with FAT Filesystem

Question

When you format a SD card you can specify whether you want to use FAT or FAT32. If you select FAT what does that actually use? Doesn't it have to be FAT12, FAT16 or FAT32?

Answer 1

I believe the FAT option uses FAT16.

Confirmed by this link on the Tom's Hardware Forums (emphasis mine).

Of course it sees and can also format FAT16 partitions: I always format my flash drives, CF and SD with FAT16, because embedded systems, like cameras and mp3 players don't read FAT32 (only the very new models).

But of course you must create a partition not larger than 2GB, because that is the FAT16 physical limit. In the Format context menu you'll find the FAT32 and FAT options. FAT stands for FAT16.

Note that, when the post says "only very new" devices read FAT32... that was posted in 2006. Regardless, I believe that answers your question.

Answer 2

FAT12 has a maximum size of 32MB and is rarely used these days. FAT16 has a maximum size of 2GB, so it's suitable (but not necessarily most appropriate) for non-HC SD cards. Beyond 2GB, you need FAT32.

FAT is a generic name for “any of the FAT variants” or “whichever FAT variant is most appropriate”, but some older software may take the 1995-ish view that FAT32 is a new thing that doesn't deserve to be called FAT.

You don't say which software you're using to format the SD card, so it's impossible to say what its FAT setting actually means. However, if it offers a choice between “FAT” and “FAT32”, it's highly likely that it uses “FAT” in the “FAT16” meaning.