Subject: Re: CCL:Athlon vs Intel performance

From: Matthias Mann <[email-masked]>
Date: Wed, 29 Mar 2000 10:26:24 +0200

On Wed, 29 Mar 2000, you wrote:
>1GHz PC's will be shipping in May (Athlon) and June (PIII).
>
>Performance comparison:
>PIII 1GHz with 133MHz bus (anyone know when 200MHz bus is expected ?)
>vs
>Athlon 1GHz with 200MHz bus (anyone know of dual Athlon mobo with 200MHz bus ?)
>
>Any comments or links would be appreciated.
>
>Any comments on CPU comparison of PIII 1GHz vs Athlon 1G  (FPU and cache 
>size/speed are the main issues ?).
>
>Discussion welcome.
>
>Laurence

I have only comparisions of PII-450, PIII-500 and AMD Athlon 550.
Look at: 
	http://www.chm.tu-dresden.de/edv/bench/bench9.html
for GAMESS(US) benchmarks, and at:
	http://www.chm.tu-dresden.de/edv/bench/bench10.html
for GAUSSIAN98 A7 benchmarks.

Normally the relation of relative performance looks as expected;
however, in some cases the Pentium-III system is extremly slow:
this is the case in MP2 and QCISD(T) calculations with Gaussian
and in CASSCF calculations with Gamess.
I'm not sure about the reason, maybe this is the cache, or the
architecture specific optimization (the code was compiled in both
cases with pgf77 on an PII system, and in the Gaussian case
maybe the optimized BLAS plays a role).

Matthias

--
Dr. Matthias Mann 
Institut fuer Organische Chemie, TU Dresden
D-01069 Dresden, Mommsenstr. 13
Tel.: +49 (351) 463-4286 / Fax: -7030
Email: [email-masked]

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From: "Dr. Peter Burger" <[email-masked]>
Date: Wed, 29 Mar 2000 12:52:22 +0200 (CEST)

Hi,

just worth my 0.02 cents

The numbers I have. show that at the same clock freq. the Athlon is
roughly 0-10 % faster on my benchmarks compared to the PIII (ADF,
Turbomole, Jaguar). Things are different for Dmol which make heavy usage
of Blas-3 dgemm, which is substantially faster on the Athlon using the
fabulous Atlas (cudos to Clint Whaley!) libarary, e.g. 

860 MFlops at 800 MHz for the Athlon compared to
825 MFlops at 750 "              "
440 MFlops at 550 MHz on a PIII (still Katmai core)

for dgemm based matrix multiplications (independent of the matrix size)

Based on figures by Intel for their new math kernel library, peformance
of a 733 MHz Coppermine is below

600 MFlops.

For Dmol this helps alot and gives a 30% performance edge for the
Athlon. But I guess most vendors that use Blas-3 libs will provide only
one version of their commercial software which is quite likely to be based
on the Intel library.

For Gaussian & Gamess etc. you can obviously choose yourself, but then
it depends how much your code depends on Blas-3. For Jaguar, there was 
a tremendous speedup in their new Linux 4.0 version (factor 2x over 
3.5) which  to the best of my knowledge is at least in parts due to the
usage of dgemm. I will post an updated version of my Linux
quantumchemistry  software comparison shortly which includes new results
for Jaguar 4.0 and Dmol on the Athlon/Linux.
 
The Athlon has still alot more potential and needs better compilers
to support its second FP pipeline (not present in the PIII) and a
faster memory bus. Compaq I heard is working on an Athlon version 
of their DVF NT Fortran compiler and supposedly they see good speedup
(taken from ct' a German computer magazine) already. Supposedly it is
due in 3 months.

The memory bus is already slightly improved with the event of the new
KX133 chipset supporting 133 MHz SDRAM. Ought to get still better though
through  the usage of DDR RAM aware chipset in the second half of this
year.  Nevertheless stream memory bandwith benchmarks went up from 
500 MB/sec on the 100 MHz bus to 600-700 MHz on the 133 memory bus 
in the new KX133 based boards.

Also, one can expect alot good things from the new Thunderbird core
which has the L2 cache ondie running at the core clock speed and which
should be out soon. At least Intels Coppermine with 256 K ondie L2 cache 
seems to have a 20% performance edge over the Katmai core with 512 K 
L2 cache running a 1/2 clockrate.

Regards,

Peter

P.S. May I ask users of the Portland group (pgi) Linux pgf77/90 Fortran
compiler (e.g. Gaussian G98 users!) to request at pgi for Athlon
optimizations in that pgi notices that there definitely is a market.
-------------------------------------------
Peter Burger
Anorg.-chem. Institut
Winterthurerstr. 190
Universitaet Zuerich

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From: "M. Nicklaus" <[email-masked]>
Date: Wed, 29 Mar 2000 15:15:02 -0500

For what it's worth:

We've run one single direct speed comparison (I wouldn't call it a benchmark) so
far, running the same Titan calculation on both a 600 MHz Pentium III
(non-Coppermine) and an 800 MHz AMD K7 (Athlon) system, both running under
Windows 98.  (The job was a single point energy calculation at the LMP2/6-31G**
level for a nucleoside analog.)

Time for completion (as per program output, but in agreement with wall time):

600 MHz Pentium III  -  7:05 h
800 MHz Athlon       -  2:25 h

Correcting (linearly) for the difference in clock rate, the Athlon is still
faster (for this job!) by a factor of 2.2.

Specs: 

600 MHz Pentium III  -  100 MHz FSB, 512 MB PC100 RAM, 27 GB ATA/66 7,200rpm HD
800 MHz Athlon       -  100 MHz FSB, 256 MB PC100 RAM, 27 GB ATA/66 7,200rpm HD

However, we've had quite a few stability problems with the Athlon system so far
(both in Titan and in general), but we think these are more likely related to
hardware driver problems in Windows 98 than to true hardware instability. All in
all, YMMV.

Marc

------------------------------------------------------------------------
 Marc C. Nicklaus                        National Institutes of Health
 E-mail: [email-masked]               Bldg 37, Rm 5B29
 Phone:  (301) 402-3111                  37 Convent Dr, MSC 4255       
 Fax:    (301) 402-2275                  BETHESDA, MD 20892-4255    USA 
      http://rex.nci.nih.gov/RESEARCH/basic/medchem/mcnbio.htm
    Laboratory of Medicinal Chemistry, National Cancer Institute
------------------------------------------------------------------------

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From: Laurence Lavelle <[email-masked]>
Date: Wed, 29 Mar 2000 13:36:54 -0800

Well that answers that. Are there any dual Athlon's expected this year ?
Thanks for all the replies.

Laurence