The file system refers to the structures that are used to organize data at a high level
on the disk; the file system is used by the operating system to store files, directories
and other relevant information on the disk for later retrieval. As such, the file system
is highly operating-system-dependent. In most cases you don't generally have a
"choice" between different file system types. However, in some operating systems
you do, and there can be a performance impact from the choice.
Some file systems store files in packages as small as 512 bytes, while others store
files in larger chunks called allocation units or clusters. Some are
very simple file systems with few features and little overhead (such as the FAT file
system used in DOS and Windows 9x), and others have many features but comparatively higher
overhead (NTFS used in NT). Windows NT and 2000 typically give you your choice of file
system; Windows 2000 supports FAT16, FAT32 and NTFS. See
here for more on the different file systems used in the PC.
Which file system you use can have an effect on overall performance, but it is
relatively small: typically a few percentage points. It's also difficult to predict
exactly what the effect will be for a given system when selecting from one file system to
another. Since the file system affects so many other usability factors of the PC,
performance is usually not one of the primary factors for deciding between them.
As an example, consider the "FAT vs. NTFS" decision, which is probably the most
common "file system decision" in the PC world today. These two file systems are
so different in so many ways that most people choose one or the other for reasons
particular to their use, not performance. If you need the high security and advanced
management features of NTFS, you are probably going to use NTFS even if FAT is a few
percentage points "faster". Similarly, if you need the compatibility and
simplicity of FAT, changing to NTFS for a few ticks on a benchmark is probably unwise.
One file system choice that is commonly made in part for performance reasons
is "FAT16 vs. FAT32"; this is really a "sub-file-system" choice, since
FAT16 and FAT32 are really two flavors of the same file system. The primary performance
impact of changing between these has nothing to do with anything inherently different
between FAT16 or FAT32, but rather the difference in cluster size that results from the
choice. See here for more details on this.
Next: Partitioning and Volume Position
