Subject: CCL: Cpu time in Gaussian output

From: Ian Hovell <HOVELL :: cetem.gov.br>
Date: Mon, 21 Mar 2005 12:39:22 -0300

Dear CCLers,
I was asked the other day about the meaning of the cpu time that Gaussian
reports at the end of a job. The value does not match with the actual time
of the calculation which can be worked out from the date stamps at the
beginning and end of the output file..
The explanation I gave was that it was the time taken for the calculation on
the cpu and the difference between that and the reported date stamps was the
time the computer was waiting to write to the hard disk, transfer data etc.
Would this be a reasonable explanation for the difference in values?
 
TIA

Ian Hovell - Ph.D. 
NUCLEO DE MODELAGEM MOLECULAR-NMM 
Centro de Tecnologia Mineral - CETEM 
Ministerio da Cincia e da Tecnologia- MCT 
Avenida Ip, No 900 - Cidade Universitaria 
Ilha do Fundo Rio de Janeiro RJ Brasil 
CEP 21941-590 
tel 00 55 (xx) 3865 7344 ou 3865 - 7216 
Fax 00 55 (xx) 22602837 ou 2290-4286 
e-mail hovell :: cetem.gov.br <mailto:hovell :: cetem.gov.br>