Subject: Summary: Risc/Silicon Graphics/multiprocessor PC/Digital ...

From: Tapas Kar <[email-masked]>
Date: Mon, 19 Oct 1998 20:34:51 -0500 (CDT)

> Hi Everybody,
> We are planning to buy a box who shall be fully dedicated for
> Gaussian94/98
> jobs and can handle(in good manner) large molecules(50-100atoms) with
say
> 300+ basis sets. How fast are the multiprocessor PC with Linux compared
to
> others say Risc/Silicon Graphics/Digital Alpha/ or other(???)?
> 
> Budget is within 30-35K.
> 

REPLIES:

In a nutshell: Speed-wise, the fastest Pentium II systems are on par,
if not faster, than (many of ) the SGI, IBM, DEC workstations/servers.  On
a bang-per-buck basis, that places the commodity-type machines WAY ahead
of the latter computers.  

Of course, then there are the Alpha based clones (to be had for <$3,000),
which are much faster again... but compilation of G9x for Alpha/Linux is
not trivial, as this platform is not (yet) supported by Gaussian, Inc., 
as far as I know.

You may be interested in our G94 benchmark paper that just came out:
"Computational Chemistry on Commodity-Type Computers", Nicklaus, M.C.
et al., J. Chem. Inf. Comput. Sci. 38(5), 893-905 (1998).
I can send you a reprint if you want; please let me know.

If you have a subscription to JCICS, you can also get it of the ACS Web
site, at http://pubs.acs.org/journals/jcisd8/index.html.

Hope this helped.

Regards,

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) 496-5839                  BETHESDA, MD 20892-4255    USA 
      http://rex.nci.nih.gov/RESEARCH/basic/medchem/mcnbio.htm
    Laboratory of Medicinal Chemistry, National Cancer Institute
------------------------------------------------------------------------
*******************
Before you invest all the money in new hardware, consider a performance
gain you
could also see from new software.  Not Gaussian, but Jaguar
(www.schrodinger.com).  Particularly for systems as large as you describe. 
Jaguar doesn't have as many features as Gaussian but it generally runs
faster
(sometimes much faster) for singlepoint energies and geometry
optimizations,
especially for systems that large.  Other types of calculations are also
faster,
due to the methodologies unique to Jaguar which speed up the evaluation of
2-
electron integrals.  You might be able to demo it to see if there is a
significant advantage for your own needs.

Bryan Marten, PhD
[email-masked]

********************
Hi! Maybe this site can help you:

http://www.cmm.ki.si/parallel/summary.html

Regards...
------------------------------)(--------------------------
Jose Luis Carreon Macedo
Quimica y Fisica Teorica,DEPg, Facultad de Quimica,UNAM,CU
Mexico,DF. 04510 email: [email-masked]

--------------------------------------------
Tapas Kar, Ph. D                           
Asst. Scientist/Asst. Professor (Adjunct)                            
Forestry Bldg 118
Department of Chemistry
Southern Illinois University at Carbondale
Illinois 62901-4409

Fax: (618) 453 6408
Tel: (618) 453 6433(Lab) 6485(Office)
--------------------------------------------