[Pw_forum] A Question About Time

[Paolo Giannozzi]

mohsen modaresi wrote:

> When i run parallel (With MPICH) version with 4 core, 
> in output file i see this "total time until now 6.06 sec."  it take 
> but if i use my watch29 sec to run. What is the problem?
> another problem:
> If i use MPICH with 1 core it takes only 17 sec (on my watch) which is 
> smaller than 29, Why?

See Sec.3, "Understanding parallelization", and sec.6.4,
"Parallelization issues", of the user guide.

P.
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy