IOzone is a file system benchmark utility. Originally made by William Norcott, further enhanced by Don Capps. Source code is available. It does mmap

Mmap

In computing, mmap is a POSIX-compliant Unix system call that maps files or devices into memory. It is a method of memory-mapped file I/O. It naturally implements demand paging, because initially file contents are not entirely read from disk and do not use physical RAM at all...

file I/O and uses POSIX Threads

POSIX Threads

POSIX Threads, usually referred to as Pthreads, is a POSIX standard for threads. The standard, POSIX.1c, Threads extensions , defines an API for creating and manipulating threads....

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It won the 2007 Infoworld Bossie Awards

Infoworld Bossie Awards

Infoworld Bossie Awards are given to the best open source software in various categories. The first of these awards was announced in September 2007, and were given to 36 software applications across 6 categories. The software was adjudged by the Infoworld editors and reviewers.- Open source...

 for Best file I/O tool.

The Windows version of IOzone uses Cygwin

Cygwin

Cygwin is a Unix-like environment and command-line interface for Microsoft Windows. Cygwin provides native integration of Windows-based applications, data, and other system resources with applications, software tools, and data of the Unix-like environment...

. Builds are available for AIX, BSDI, HP-UX

HP-UX

HP-UX is Hewlett-Packard's proprietary implementation of the Unix operating system, based on UNIX System V and first released in 1984...

, IRIX, FreeBSD

FreeBSD

FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...

, Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

, OpenBSD

OpenBSD

OpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution , a Unix derivative developed at the University of California, Berkeley. It was forked from NetBSD by project leader Theo de Raadt in late 1995...

, NetBSD

NetBSD

NetBSD is a freely available open source version of the Berkeley Software Distribution Unix operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design,...

, OSFV3, OSFV4, OSFV5, SCO OpenServer

SCO OpenServer

SCO OpenServer, previously SCO UNIX and SCO Open Desktop , is, misleadingly, a closed source version of the Unix computer operating system developed by Santa Cruz Operation and now maintained by the SCO Group....

, Solaris, Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

, Windows (95/98/Me/NT/2K/XP).

It is available as a test profile in the Phoronix Test Suite

Phoronix Test Suite

Phoronix Test Suite is a free, open-source benchmark software for Linux and other operating systems developed by Phoronix Media with cooperation from an undisclosed number of hardware and software vendors....

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