rrr@u02.svl.cdc.com (Rich Ragan) (04/09/91)
There has been discussion in the past about trying to separate
out the effects of compilers from the underlying hardware performance.
Control Data has just submitted the following SPEC numbers for
publication. [A Control Data 4680 is the same as a Mips 6280,
although the multi-processor version will be different. This data is
from a vanilla scalar 4680 and so should be completely equivalent to
a 6280.]
The only thing we changed was to use a new FORTRAN compiler jointly
developed with Kuck and Associates for the multi-processor CDC 4680.
As it turns out, the compiler does optimizations which help single
processor machines as well. This data provides insight into what
changing the compiler and holding the machine constant can do to the
performance of the machine/compiler combination.
-----------------------------------------------------------------------------
gcc espr. li eqntott spice doduc nasa7 matrix fpppp tomcatv
-----------------------------------------------------------------------------
Mips 6280 46.0 42.4 54.6 41.2 38.4 43.0 45.6 49.8 55.6 43.3
CDC 4680 46.0 42.4 54.6 41.2 40.3 44.0 62.4 181.7 56.5 57.5
-----------------------------------------------------------------------------
The Mips SPECmark is from our runs using the upcoming 2.20 compilers.
I think they may have reported something a little higher (~46.5).
Mips 6280 SPECmark: 45.7, IntSpecs: 45.8, FPSpecs: 45.6
CDC 4680 SPECmark: 55.7, IntSpecs: 45.8, FPSpecs: 63.5
--
Richard R. Ragan rrr@svl.cdc.com (408) 496-4340
Control Data Corporation - Silicon Valley Operations
5101 Patrick Henry Drive, Santa Clara, CA 95054-1111mccalpin@perelandra.cms.udel.edu (John D. McCalpin) (04/09/91)
>> On 8 Apr 91 17:02:48 GMT, rrr@u02.svl.cdc.com (Rich Ragan) said:
Rich> There has been discussion in the past about trying to separate
Rich> out the effects of compilers from the underlying hardware performance.
[......]
Rich> The only thing we changed was to use a new FORTRAN compiler jointly
Rich> developed with Kuck and Associates for the multi-processor CDC 4680.
-----------------------------------------------------------------------------
gcc espr. li eqntott spice doduc nasa7 matrix fpppp tomcatv
-----------------------------------------------------------------------------
Mips 6280 46.0 42.4 54.6 41.2 38.4 43.0 45.6 49.8 55.6 43.3
CDC 4680 46.0 42.4 54.6 41.2 40.3 44.0 62.4 181.7 56.5 57.5
-----------------------------------------------------------------------------
^^^^^
I have worried about the inclusion of the 'matrix300' code in the SPEC
suite, as it is such a simple calculation mathematically that it is
possible that special compiler techniques can be used to greatly
enhance the performance without necessarily helping the performance of
more general codes.
In this case, the LINPACK routines SGEMV, SGEMM, and SAXPY are used.
It is well known that SGEMM can show very large improvements by
hand-coding (I get a 33 MFLOPS vs 6 MFLOPS on my IBM RS/6000-320 by
hand-coding), so an "SGEMM-recognizer" could short-circuit the
usefulness of this benchmark considerably. Note that the new
HP9000/730 gets a score of 273 on this test, which raises its SPEC
floating-point rating considerably!
This is not to suggest that Kuck & Associates did it this way, but the
block-mode approach that is so helpful on matrix operations is of much
more limited utility on more general array operations.
P.S. Tell us more about the multiprocessor CDC 4680!!!!
--
John D. McCalpin mccalpin@perelandra.cms.udel.edu
Assistant Professor mccalpin@brahms.udel.edu
College of Marine Studies, U. Del. J.MCCALPIN/OMNET