A file system (also known as filesystem) is a technique for storing data in an organized and a human-readable form. The basic unit of a data file system is called a file. A file system is a very important component residing in most data storage devices like hard drives, CDs and DVDs. A file system helps the devices to maintain the physical location of the files. Furthermore, a file system can allow its files to be accessed from a network by becoming a client to network protocols like NFS (Network File System). FAT and NTFS are two of the file systems used in Microsoft Windows operating system. Actually, FAT (File Allocation Table) was the default file system used in older Windows versions. Starting from Windows XP, NTFS has replaced FAT as the default file system.
What is FAT?
FAT was the default file system used in older Windows versions (before Windows XP). Still, FAT can be used with floppy disks and older Windows versions (for multi-boot systems). FAT gets its name due to the use of a special type of a database called File Allocation Table. Each cluster on the disk has a corresponding entry on the table. FAT was initially used with DOS, and its three versions are FAT12, FAT16 and FAT32. The number of bits used to identify a cluster is the number that is used as the suffix in the name. FAT12, FAT16 and FAT32 have 32MB, 4GB and 32GB as the maximum partition sizes. Although the initial systems were unable to read larger hard disks, Microsoft had to extend the FAT system continuously, due to the rapid increase of hard disk sizes. But, ultimately Microsoft had to replace FAT with NTFS (which is much more suitable for larger disks). Recently, FAT system is making a small come-back as thumb drives have started using FAT. Sizes of the current flash drives are inherently small, so FAT system clearly suits them.
What is NTFS?
NTFS is the default file system currently used in Windows operating systems. NTFS took over from FAT as the default file system starting from Windows XP. Consequently, Windows NT 4.0, Windows 2000, Windows XP, Windows .NET server, and Windows workstation use NTFS as their preferred file system. NTFS has completely different data organization architecture. Basically, Microsoft developed NTFS to compete with UNIX, by replacing the much more simple FAT. A FAT partition can be easily converted to a NTFS partition without loosing data. NTFS supports features like indexing, quota tracking, encryption, compression and repair points.
What is the difference between NTFS and FAT?
FAT was the default file system in older Windows versions, while NTFS is the current file system in its place. NTFS has more flexibility than FAT. The reason for this is the fact that FAT uses fixed structure in its system areas, but NTFS uses files. Because of the use of files, it is very easy to modify, extend or move as required. For example, the MFT or Master File Table is a system file used in NTFS, which is similar to a relational database system. The way the clustering is used in NTFS for the assignment of space is also different from FAT. NTFS’s maximum cluster size is 4kb, while file compression is included to avoid slack.
But the downside of having the MFT and other system files (which takes up lots of space) is that NTFS is difficult to be used with smaller disks. That is why FAT is still used for thumb drives. NTFS also requires more memory than FAT. Built-in security measures in NTFS are far better than in FAT, because it is intended for multi-user environments. For example, permissions and encryptions can be applied to even individual files in Windows XP Professional edition. But on the other hand, forgetting a password in Windows XP is much problematic than in Windows 98 (which used FAT), because it is very difficult to troubleshoot and tweak with NTFS. Furthermore, the newest FAT version called exFAT is claimed to have certain advantages over NTFS.