STREAM Logo (Image)Department of Computer Science
School of Engineering and Applied Science
University of Virginia, Charlottesville, Virginia

What's New!

List of the 30 newest entries!

2007-06-18: New version of STREAM in Pascal!

So how many of you are there are old enough to remember a programming language called "Pascal"? I recall doing a little bit of programming in Pascal using the UCSD Pascal "p-code" integrated development environment on an Apple ][ computer.
A participant in the Free Pascal project donated a Pascal version of STREAM that I have placed in the Contrib area.

2005-02-07: Re-organization of the STREAM ftp site

The Department of Computer Science at the University of Virginia has discontinued anonymous ftp service. So I have moved the stuff that used to only be available by ftp into a new directory that can be accessed by http here.

2004-11-17: Re-organization of the STREAM ftp site and file names

The most recent "official" versions have been renamed "stream.f" and "stream.c" -- all other versions have been moved to the "Versions" subdirectory.
The "official" timer (was "second_wall.c") has been renamed "mysecond.c". This is embedded in the C version ("stream.c"), but still needs to be externally linked to the FORTRAN version ("stream.f").

2004-11-17: New "Getting Started" section in FAQ

Due to a number of recent requests for help in getting started, I have renamed the files and added some new "Getting Started" instructions in the FAQ.

New Opteron Binary

A STREAM binary for Opteron/Athlon64 has been submitted to the STREAM web site. It is reported to work on SUSE, Red Hat, and Fedora. Give it a try, and let me know if it works!
Here is the link to the submission.

2003-09-23: Minor change in reporting for MPI runs

After reviewing several requests, I have decided to allow a subset of MPI results to be published in the "standard" table. The specific case that I allow is when the MPI version of the code is used to run the STREAM benchmark on a single SMP system.

I do not require that all of the MPI processes run under a single O/S, only that the hardware supports shared memory operation that would allow a single O/S to be run if so configured. These "MPI on SMP" results are marked with the notation "(MPI Result)" on the standard benchmark page, and these results are eligible for inclusion in the "TOP20" list.

For completeness, these results will also continue to be included in the MPI table.

Feel free to flame me if you think that this is a bad idea. e-mail flames here

2002-12-04: Estimating Sustainable Bandwidth using SPEC CPU2000 Results

I have written up my methodology for estimating STREAM Triad bandwidth using published results from the 171.swim benchmark in SPEC's CPU2000 suite. These are not publishable STREAM results, but they definitely give a good rough estimate on a wide variety of systems.

2002-12-04: Estimating SPECfp_rate2000 using Peak GFLOPs and STREAM Triad (PowerPoint presentation)

This is a slightly updated version of a presentation that I made at the TOP500 meeting at SuperComputing2002 in November. The slides show a methodology for getting reasonably accurate estimates of SPECfp_rate2000 using only one measurement, plus a set of architectural parameters of the system.

2002-11-05: A new category of results has been defined!

In response to popular demand, a new category has been created explicitly for "tuned" results. This category allows source code modifications to increase performance, including assembly language coding.

2002-11-05: The "Top10" list has been extended to the "Top20" list.

"Top20" list is drawn from both the "standard" and "tuned" results. This provides a "show-off" category to allow folks to show off the best realizable performance on their systems, similar to the LINPACK NxN (aka LINPACK HPC) benchmark.

2002-06-25: An MPI version of STREAM has been released.

Check it out.

2002-02-25: An OpenMP version is available in C!

Version 4 of the STREAM benchmark in C is now available with OpenMP directives. This version still does not have the error-checking or anti-optimization code that is contained in version 5 (still FORTRAN only), but it does allow shared-memory parallel execution on many systems!

2000-07-30: Version 5 of the STREAM benchmark is ready!

Version 5 of the STREAM benchmark is available for FORTRAN users.

New features include:

  • OpenMP directives for parallel execution on many shared-memory machines
  • Added a new subroutine to validate results
  • Added modifications to array elements to prevent aggressive optimizers from moving the timer calls. (This is a problem with IBM's XLF 7.1 when using prior versions of STREAM.)
  • Switched from RMS time to AVG time in output.  (Min time is still used to calculate the bandwidths.)
  • STREAM now excludes the first and last iterations when looking for minimum times.

    • 2000-04-18: All e-mail contributions caught up!

    I am still working on adding links from the original submissions to the entries in the tables.  All are complete for the submissions in 1996 and 2000, and I am working toward the middle.....

    I also switched from 68k Linux to PowerPC Linux for my home machine, so I have a much more complete set of tools.  Look for STREAM listings for the PowerComputing PowerCurve 601/120.

    2000-04-18: FAQ Revised and Updated!

    The STREAM FAQ has been revised and updated with a much more useful discussion of the STREAM benchmark run rules. Check it out!

    What's Not so New Any More!

    99.11.10: e-mail updates

    I have updated the hypermail archives of the original submissions of STREAM results. Not everything has made it into the tables yet, but I am slowly catching up.

    99.10.29: New Categories for PC's and Mac's NEW!

    I have added tables for "standard" results for PC's (and compatibles) and Macintosh's (and compatibles).  "Non-standard/experimental" results and "32-bit" results are still in the corresponding tables -- these tables are small enough that you can find the Mac and PC results easily enough.

    99.10.29: Links to Original Data NEW!

    I am beginning to add links from the data pages back to the original e-mail submissions (in hypermail format).  Unfortunately, this is an entirely manual process, so it is going to take a while.  I also have the problem that I cannot get the new version of hypermail to compile on my AIX machine, so it will probably be slow going until I get Linux up on my Mac (68k) at home.

    99.10.18: I'm back!

    STREAM's author and maintainer (that would be me) is back. I just moved from Silicon Valley to Austin, TX, and have had a bit of trouble getting all my computers and accounts configured.
    As of Monday, October 18, 1999, STREAM is back in business, and I will be happy to accept results and will get them in the tables promptly.

    99.10.18: AMD Athlon (aka K7) Results!!!

    The first results from the new AMD Athlon (aka K7) are in, courtesy of Claus Jeppesen (jeppesen@mrl.ucsb.edu). This machine is a screamer, posting over 450 MB/s on three of the four kernels! Watch out Intel!

    Summer 1999: New Reporting Rules for Systems with Multiple Independent Memory Subsystems!!!!

    A Change of Categories for Some Multiprocessor Results: A "partially depopulated" system is one in which only a subset of the cpus are used for the benchmark, and for which this subset is spread around the machine to decrease contention. For example on the SGI Origin2000, each node has 2 cpus sharing a single bus and memory subsystem. The results in the "experimental/nonstandard" table labelled "1 per node" are based on using only one cpu per node board, and are considered a "nonstandard" way of using the machine. Similarly, the Sun Ultra10000 has 4 cpus per node board, so results using 1, 2, or 3 cpus per node also go into this table of "nonstandard" results.

    From this point forward, "partially populated" results will no longer be included in the table of "standard" results -- only "fully populated" multiprocessor results will be considered "standard". "Partially populated" results are still welcome, but will be placed in the "experimental/nonstandard" tables, which have been renamed (from simply "experimental") to more clearly denote the non-standard use of the hardware.

    Summer 1999: Linux Executables for IA32

    There are some new contributed sources and binaries in the MasonCabot directory.

    The linux executables run great on Pentium II & Pentium III machines. We are still a bit puzzled by the Windows NT Server results. Any gurus out there willing to help out?

    NEW! 99.10.18: Mason Cabot and I figured out that the poor results under Windows NT were the result of a misconfiguration on my part. My Linux boxes all had the full complement of SIMM's installed, while the NT machines had the minimum configuration. Apparently the Intel chipset used in this box (the SGI 1400) requires a fully loaded memory system to reach full bandwidth.NEW!
     

    Mac PowerPC executable set

    A set of Mac executables is available now in Stuff-ed format. Get your own copy.
     

    Really OLD News

    An Old DOS version

    Dennis Lee has revised a version of STREAM for DOS machines. The executable and a README file are available in a zip file.

    Mailing List Archive

    I have created a mailing list to discuss future developments of STREAM and memory bandwidth benchmarking in general. The archives of the mailing list are here in hypermail format.

    Hypermail archives of old e-mail

    Thanks to some friendly pointers to the right tools, the five years of contributions to the STREAM archive is now available for surfing. Go here for whatever details exist on machine details, compilers, compiler options, etc....

    New Results in 1996:

    May 12, 1996:

    There has been a complete change in the underlying structure of the database. The entire database of raw results is now contained in a single, comma-delimited datafile. This is described in the Table subdirectory.

    Contributions in 1995

    John D. McCalpin mccalpin@cs.virginia.edu