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exFAT Versus FAT32 Versus NTFS

With Vista SP1 Microsoft has introduced a new file system. Extended File Allocation Table (exFAT) is the successor to the old FAT32 file system. What are the advanatages and disadvantages to this new file system? What are the differences between exFAT and FAT32? When is exFAT preferred over NTFS?

Microsoft has released the exFAT file system with Vista SP1. This file system that previously had been rumored to be released with the original Vista is finally available to the public on a wide scale. This article will explain what issues with FAT32 that exFAT fixes. Surprisingly to many people, exFAT even may be better than the much loved NTFS in some circumstances.

FAT32 is the file system with which most windows users are most familiar. Windows first supported FAT32 with Windows 95 OSR2 and has increased support for it through XP.

FAT32 has multiple issues that modern systems can experience:
- By default windows systems can only format a drive up to 32 GB. Additional software works around this issue. When formatted at these bigger sizes, FAT32 becomes increasingly inefficient.
- The maximum file size on a FAT32 formatted drive is around 4 GB. With DVD and high resolution DVD formats now available, this limit is commonly noticed.
- Dealing with fragmentation and free disk space calculations can become painfully resource intensive in large FAT32 systems.
- A FAT32 directory can have 65,536 directory entries. Each file or subdirectory can take up multiple entries; therefore, FAT32 directories are limited with how many files it can hold.


exFAT was first released with CE 6.0 but will finally hit the mainstream with Vista SP1. exFAT has several advantages over FAT32:
- File size limit is now 16 exabytes.
- Format size limits and files per directory limits are practically eliminated.
- Like HPFS, exFAT uses free space bitmaps to reduce fragmentation and free space allocation/detection issues.
- Like HTFS, permission systems should be able to be attached through an access control list (ACL). It is unclear if or when Vista will include this feature, however.

In the past most power-users of Microsoft systems have opted to format/convert to a NTFS file system instead.

Interestingly enough, exFAT is not used currently for formatting hard drives. It is being recommended in Flash memory storage and other external devices only. This is why it is currently not considered a huge competitor to NTFS on hard drives.

However, exFAT should be a true competitor to NTFS on systems with limited processing power and memory. NTFS on flash memory has been known to be inefficient for quite some time. exFAT's smaller footprint/overhead makes it ideal for this purpose. Of course, only if your definition of "ideal" allows software to be proprietary and not open source.

Vista will happily read FAT, exFAT, and NTFS from flash. ReadyBoost may not work with exFAT formatted flash drives, however.

In conclusion, basically, FAT is a simple system. This limits FAT system by losing efficiency at large sizes, but allows it to run with less resources. The complexity of NTFS increases features but requires more memory and processing power.