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	FAT versus NTFS We are often asked, "Which format is better, FAT or NTFS?"The answer is really quite simple, once you understand the basic differences between the two. (NOTE: In this article,we refer only to FAT-16, not FAT-32, since NTFS does not support the FAT-32 format.) FAT stands for File Allocation Table. This table is located at thestart of the partition. It contains information about how and where the files are stored on the partition. In FAT,critical file system data is not duplicated; the loss of a single critical sector can result in the loss of everythingon the partition. The File Allocation Tables and the root directory must be at fixed locations, so that the filesneeded to start the system can be located. The FAT format can be used by several operating systems, includingMS-DOS, Windows 3.1x, Windows 95 and Windows NT. It can handle a maximum of 65,535 clusters, and a maximum of 65,518files. FAT is best suited for smaller partitions (roughly, to 500MB). Onpartitions larger than 500MB, the cluster size must be 8KB or more, since FAT will only support 65,535 clusters.Plus, the available cluster sizes are limited; they must be a power of 2. That is, you cannot have a 10KB clustersize; you would have to use 16KB or more. This increases the wasted space due to unused space in the last clusterof a file. Of course, if you only have very large files on the partition, this wasted space is not significant. NTFS stands for New Technology File System. Central to it is the MasterFile Table, or MFT, essentially an index to all of the files on an NTFS volume. The critical data is duplicated,so that the loss of a single sector cannot cause you to lose the entire partition. See the article The Master File Table (MFT) for details. NTFS includes advanced security features, such as data access controland ownership privileges. Files and folders can have permissions, specifying whether the files are shared or not,and permissions can also be assigned to individual files. However, these permissions and attributes will be lostif the file is transferred to a FAT partition. NTFS can only be used by Windows NT. It is much more fault-tolerantthan FAT. NTFS includes recovery capabilities, which ensure that the file system can be recovered in the eventof a catastrophic system failure. It can also recover data from a bad sector and it will automatically allocatethe bad sector to a special file, so the bad sector will not be used again. The maximum NTFS partition size is 2TB (terabyte, a trillion bytes).NTFS actually has an upper limit of 16 exabytes (quintillion bytes, or 16 million TB), but since current industrystandard limits the Partition Tables to 2 to the 32nd power sectors (with 512B sectors, that's 2 TB), the actualcurrent upper limit is 2 TB. NTFS does not limit the number of files you can have on a partition;the volume size, and thus the number of file entries you can fit into the MFT, sets the limit. NTFS is more efficientthan FAT for larger volumes (roughly, more than 500MB). Microsoft recommends using a small (250MB to 500MB) FAT partitionfor the system partition (which contains the hardware-specific files used in loading and initializing the operatingsystem) and for the boot partition, and using NTFS for the rest of your partitions. In fact, on RISC-based partitions,the system partition must be a FAT partition. On an x86 system, one of the advantages of this setup isthat if you have a startup failure you can boot from a bootable DOS floppy to repair the system. So, here are the guidelines: If you will have more than 65,518 files, you must use NTFS If your partition is to be accessed by any operating system otherthan Windows NT, you must use FAT. If you have a RISC-based system, the system partition must be FAT. If data recoverability is important, you should use NTFS. If data security is important, you should use NTFS. If the partition is less than 500MB, FAT is more efficient. If the partition is greater than 500MB, NTFS is more efficient.   If you have any comments about this article orany requests for new technical articles e-mail
	Executive Software Europe