This article covers an important limitation of FAT32 and introduces exFAT as an alternative along with a small history of the File Allocation Table (FAT) file system.

It is the oldest file system for Windows OS and is mainly designed for removable media. It first came out as FAT12 (12 refers to the size ‘in bits’ of the FAT entries in the actual FAT structure), and by the time as the storage media size increased, more types were developed to increase the number of bits, so we got FAT16, FAT32 and finally exFAT (Extended FAT aka FAT64).

While, FAT12 was designed for small media at its time such as Floppy Disks, exFAT was introduced by Microsoft to best suit USB Flash Drives now a day.

FAT is good for removable media because it is considered to be a light-weight file system due to its simplicity (e.g. it was not designed to support security or access rights). Nevertheless, FAT can be recognized by outdated systems, for instance, FAT12 and FAT16 are recognized by all operating systems from MS-DOS forward and FAT 32 from Windows 98 forward.
FAT16, FAT32 and exFAT may be used for Hard Disks for storage purposes or even for Windows installation, but this will be on the price of losing NTFS benefits. However, Win98 does not support NTFS, so its case is different.

Why exFAT?

One day I was trying to format my 80 GB external hard disk with FAT32, instead Vista surprised me with exFAT as an alternative option (It was the first time I deal with exFAT). After checking what Microsoft had about this issue, I came across this in one of their papers:

”The largest volume size supported by FAT32 on-disk structures is 2 terabytes. Windows 2000 and later versions further limit the size of a volume that can be formatted with FAT32 to 32 GB. Because the maximum size of a file on FAT32 is limited to 32 bits, it cannot be used to store files larger than 4 GB.” [1]

This explains it all, especially that removable media over 32 GB are widely used. However, if the media size is below 32 GB, Vista allows you to format with FAT32.

After all, it appears that we can still force a FAT32 file system on media bigger than 32GB by using a software, but be warned because FAT32 will become ineffective (Windows has stopped it for a reason).

In conclusion, FAT might not be as advanced as NTFS, but its simplicity and usability should be appreciated as it requires less recourses.

References

[1] local file systems in windows, http://www.microsoft.com/whdc/device/storage/LocFileSys.mspx Accessed Dec, 2009.
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