by David Kirk | tech-recipes.com
Microsoft introduced the new exFAT file system with Vista SP1. 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 released the exFAT file system with Vista SP1. The file system that had been rumored to be released with the original Vista was finally available to the public on a wide scale. This article will explain the issues that exist with FAT32 that exFAT has been designed to fix. 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 increased support for it through XP.
FAT32 Issues and Problems
- 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 reached.
- 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.
- 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.
exFAT was first released with CE 6.0 but finally hit the mainstream with Vista SP1. Obviously, exFAT has several strengths over FAT32. Then why In the past have most power-users of Microsoft systems have opted to format/convert to a NTFS file system instead?
Interestingly enough, exFAT is not used and was not designed for formatting hard drives. It is only 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 flash-based 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 will not work with exFAT formatted flash drives in Vista, however. Windows 7 will read all three formats and can ReadyBoost exFat flash drives. Modern versions of OS X after Snow Leopard (10.6.5) added exFat read and write capabilities.
In conclusion, FAT32 is a simple system. The simplicity of FAT32 causes it to lose 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. exFAT is an improved and more complex system than FAT but is designed for flash drives only.