NTFS has so many advantages over the dreadfully archaic FAT file format that is difficult to know where to start listing them. Suffice it to say that on almost every count, NTFS is better or equal to FAT format. And so it should be considered the disk format of choice for serious NT Server and Workstation users.
There is only one real reason for using FAT format: to maintain compatibility with DOS, thus allowing for dual-booting back to Windows 3.x or Windows 95.
Amongst all the claimed advantages of NTFS is the one that suggests that an NTFS disk partition can't become fragmented, where a file gets scattered across the disk in small pieces like confetti. Obviously such fragmentation is not good for performance, because the drive has to do multiple seeks in order to read the whole file, rather than just reading the file straight in one gulp.