NTFS and FAT Performance
Too many modern data file systems or buffered cached in memory, thus avoiding
the use of unnecessary physical operations reading data from the disk. For the
normal (high) work in the system have to store cached following types of
information: data on the physical location of all open files. This is, after all,
would apply to system files and libraries, access to which is literally
constantly, without reading performance (not relevant to their own files)
information from the disk. The same applies to those files, which are executed
at the moment - that is, to perform modules (. exe and. dll) of active processes
in the system. This category also get the files with which the work is done (primarily
inventory and virtual memory, different. Ini files, as well as documents and
files applications). The most frequently used directories. These include desktop,
Start menu, system catalogs, directories Internet cache, etc. Data on the disk
free space - that is, the information that will allow to find a place to
preserve the new data to disk. If this basic information will not be immediately
available in RAM, the system will have to perform many unnecessary operations
even before it starts working with real data. What's in those quantities in
different file systems? Or, the issue in a more practical way, how much free RAM
should have to work effectively with one or another file system? FAT16 is very
little data responsible for the organization of the file system. Out of the
office areas can be identified himself only area FAT, which may not exceed 128
KB (!) - This area is responsible for finding and fragments of files, and search
for free space on the volume. Catalogs FAT system is also very compact. The
total memory required for an efficient work with the billing FAT- could range
from hundreds of kilobytes and up to megabytes next subject to the vast number
and size of directories, which are working. FAT32 different from FAT16 only that
the area itself FAT can be more impressive dimensions. At volumes around 5 - 10
gigabytes area FAT volume may take a few megabytes, and this is already a very
impressive amount, which reliably caching is not possible. Nevertheless, state
FAT, but rather those fragments, which are responsible for the location of the
working files, in the vast majority of systems are in memory of this machine has
spent some few megabytes of RAM.
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