GMPBench for Sun Fire T2000

Timothy Jacobson Timothy.Jacobson at Sun.COM
Tue Apr 25 19:28:02 CEST 2006

As a Sun Engineer, this doesn't surprise me.  The architecture is very
different for this kind of server than a single cpu desktop machine.
Machines like the Sun Fire T2000 are intended for throughput with many
threads running.  There is a trade off for having fast multi threaded
processes running parallel vs. performance for a single cpu process.
They were designed to be web hosting and data base machines, not
scientific computing engines.  When all 32 virtual processors are in
motion, this outperforms any single cpu desktop you can find.

The other problem is that the performance in the GMP code is mostly gnu
specific inline code for x86 processors.  I have worked on a patch that
produces fantastic numbers for Sun Opteron machines.  I have given some
thought to writing a threaded version of the GMP library.  That is not
an easy task.  Maybe not possible.  Does anyone have interest that would
justify my effort?  I don't want to waste time doing something nobody
wants or can't be done.

By the way, thanks for running the benchmark.  At Sun, we welcome the
input.  We are always looking for ways to improve our products and I
will pass this information on to other engineers to look at.

Kind regards,

Tim Jacobson

Torbjorn Granlund wrote On 04/25/06 03:42,:
> Greg Childers <jgchilders at> writes:
>   Here's a GMPBench result for a Sun Fire T2000 server.  I used only 1 
>   of 32 virtual processors during the bench.
>   GMPbench result: 62.246
> These numbers are worse than a 15 year old 68040.  They say Sun's
> the world leader in the market segment for very slow processors,
> but a score more than 100 times worse than an Opteron?  Wow,
> Sun's way ahead in its market segment.  :-)
> How was the system identified when you ran configure?  What *.asm
> files do you find in the build directory's "mpn" subdirectory?

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