High Performance File System (HPFS)

The HIGH PERFORMANCE FILE SYSTEM (HPFS) is the Microsoft Windows NT (prior to NT 4.0) and IBM OS/2 alternative to the standard DOS FAT (File Allocation Table) file system. HPFS file systems allow extended attributes (EAs), long filenames (not the 8+3 DOS format), and are more resistant to fragmentation than FAT file systems. HPFS file systems also preserve case; that is, filenames can have upper and lower case letters. Windows 95 and DOS do not support the HPFS file system; any HPFS partitions on a computer will be invisible to Windows 95 and DOS. Also, only OS/2 applications can see the long filenames of an HPFS partition.

An HPFS file system can be faster than FAT file systems on large (>100MB) hard disk partitions. However, because the HPFS file system uses additional memory, it is not a good choice for memory-constrained OS/2 computers, especially those with less than 6MB.