High Performance File System
| Developer(s) | Microsoft, IBM | 
|---|---|
| Full name | High Performance File System | 
| Introduced | November 1989 with OS/2 1.2 | 
| Partition IDs | 0x07(MBR) | 
| Structures | |
| Directory contents | B tree | 
| File allocation | B+ tree | 
| Bad blocks | List | 
| Limits | |
| Max volume size | 64 GB (as implemented) 2 TB (theoretical) | 
| Max file size | 2 GB | 
| Max no. of files | Unlimited | 
| Max filename length | 255 characters | 
| Allowed filename characters | Single-byte from 0x20to0xFF | 
| Features | |
| Dates recorded | Access, Creation, Modified | 
| Forks | Yes | 
| Attributes | Read-only, hidden, system, archive | 
| File system permissions | Yes (only in HPFS386) | 
| Transparent compression | No | 
| Transparent encryption | No | 
| Other | |
| Supported operating systems | OS/2, Windows NT, Linux, DragonFly BSD, eComStation, ArcaOS | 
HPFS (High Performance File System) is a file system created specifically for the OS/2 operating system to improve upon the limitations of the FAT file system. It was written by Gordon Letwin and others at Microsoft and added to OS/2 version 1.2, at that time still a joint undertaking of Microsoft and IBM, and released in 1988.