Parallel version slower than the serial one

General questions and postings pertaining to the use of HYSPLIT regardless of the platform. For platform specific questions, use the HYSPLIT Platform forums.
Post Reply
Fabio.Dioguardi
Posts: 24
Joined: August 17th, 2018, 12:36 pm
Registered HYSPLIT User: Yes

Parallel version slower than the serial one

Post by Fabio.Dioguardi » February 14th, 2020, 5:54 am

Hi,

I am facing this issue with the parallel version.
I have compiled it with mpich by amending the Makefile.inc file, and it successfully generated the parallel executable (hycm_std). I am now running a test case both with the serial code (as usual) and parallel. The serial code took less than 8 seconds, the parallel one 58 seconds.
I have launched the parallel version with this command:

time sh ../../../../../hysplit.v4.2.0/exec/run_mpi.sh 10 hycm_std

after amending run_mpi.sh to point at the location of mpich executables and HYSPLIT executables (see attached). Note that the output files from each processor (MESSAGE, VMSDIST) have been generated, and I also cross-checked it was actually using 10 processors during runtime.

I have noticed that other people experienced the same issue; I also raised this point some time ago (with no answers so far), but I hoped to solve this with the installation of the latest version.
Is there anything else I need to do to make the parallel version really efficient?

Thanks
Regards
Fabio
Attachments
SETUP.CFG.txt
(561 Bytes) Downloaded 3 times
CONTROL.txt
(1.35 KiB) Downloaded 4 times
run_mpi.sh.txt
(2.65 KiB) Downloaded 3 times

ariel.stein
Posts: 642
Joined: November 7th, 2012, 3:14 pm
Registered HYSPLIT User: Yes
Contact:

Re: Parallel version slower than the serial one

Post by ariel.stein » February 14th, 2020, 1:20 pm

Can you please try to modify the CONTROL file to run with only 1 species?

Post Reply