[Openmcl-devel] Fun with Measurements
bfulg at pacbell.net
Sat Oct 28 23:28:47 PDT 2006
I re-ran the benchmarks with the current OpenMCL 1.1 snapshots, both
in the standard 32-bit PPC and 64-bit PPC.
You can see the results on http://openmcl.org/openmcl-wiki/HowFastAreWe
I think the results are interesting; SBCL is substantially faster
than any of the OpenMCL variants on several benchmarks, but OpenMCL
is outstanding in a few others.
Some of the worst cases are the BIGNUM-related routines (see the
scores on BIGNUM/ELEM-10000-1, BIGNUM/PARI-200-5, and PI-DECIMAL/BIG
for some especially egregious cases). SBCL also seems to have
superior floating point support, as evidenced by the huge performance
difference in MRG32K3A (a multiply-recursive random number
generator) , FFT, and ?.
While the 64-bit build of OpenMCL looks great on nearly all tests
(and substantially improves over the 32-bit build in some cases),
something seems very wrong with the 64-bit support for BIGNUMS (see
BIGNUM/PARI-200-5, PI-DECIMAL/BIG and PI-DECIMAL/SMALL for example).
Remember that the non-reference columns are relative scales, so on PI-
DECIMAL/SMALL, 64-bit OpenMCL is 10x as slo as OpenMCL 1.1/1.0 in 32-
bit. One small bright spot is the CRC40 benchmark, which due to it's
heavy use of 40-bit integers is substantially improved using native
A very puzzling result is that of the various ARRAY benchmarks.
While SBCL is extremely slow for the 1D case, it shows remarkable
performance in the 2- and 3-D array tests. Perhaps SBCL's internal
representation of ARRAY is optimized for the more-common 2- and 3-D
specializations, or perhaps the difference is due to SBCL's seemingly
more efficient list implementation. (see also the TAKL and WALK-LIST/
Maybe someone smart could take a look at what might be causing such a
huge bottleneck in the 64-bit BIGNUM implementation...
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