Enable parallel computing in LIGGGHTS

Submitted by rahulsoni on Tue, 11/19/2013 - 10:33

I am using LIGGGHTS but it uses only one processor for computing. I have installed LIGGGHTS by following http://cfdem.dcs-computing.com/?q=node/1789

None of the combination like processors 1 2 1 or processors 2 1 2 works...

Don't know whether LIGGGHTS is not multi-processor because no processor settings were made during compilation. Do I need to install LIGGGHTS with some added settings or feature can be added later.

aaigner's picture

aaigner | Tue, 11/19/2013 - 11:16

Hi,

How do you start your simulation? Don't forget to use mpirun, for instance,
mpirun -np 2 liggghts -in in.script
(This will only work with processors 1 2 1 and not processors 2 1 2. The latter would require '-np 4')

Bests,
Andi

govind | Thu, 07/20/2017 - 09:32

Hi Andi

I am following the same command for parallel but do not work. Liggghts installation is working fine for serial way but when I go for parallel via "mpirun -np 4 liggghts -in in.script" , it does not work. MPI is installed.

Govind

rahulsoni | Tue, 11/19/2013 - 14:42

Thanks thanks a lot Andi. For such a very useful info.

Thanks again :)

--
Regards

Rahul Kumar Soni
Scientist, CSIR - IMMT, India

rahulsoni | Wed, 11/20/2013 - 17:31

Paul, I think I am too small to answer your question. Actually, I have not tried pouring particles in multi-core. My simulation were already on the go and I just added the processors command and restarted the simulations.

--
Regards

Rahul Kumar Soni
Scientist, CSIR - IMMT, India

rahulsoni | Fri, 11/22/2013 - 16:33

Sorry Paul, for the disappointment caused to you. Just want to mark my experience.

Actually, I am running two simulation (similar kind of) simultaneously in a laptop with i7 processor. Earlier, simulations were running with single processor. Thereafter, I assigned 4 processors to each one and I noticed the nearly doubled speed.

--
Regards

Rahul Kumar Soni
Scientist, CSIR - IMMT, India

cstoltz | Fri, 11/22/2013 - 17:29

Paul,

If you're looking for some benchmarks including parallelization efficiency, check out the document linked in the 'Announcements' section at the top of the page.

Regards,
Chris

govind | Thu, 07/20/2017 - 15:19

While running in parallel I get following error :

ERROR: Invalid dump style

Here is the dump command :

dump dmp all custom/vtk 10000 post/dump*.vtk id type type x y z ix iy iz vx vy vz fx fy fz omegax omegay omegaz radius

Govind

aaigner's picture

aaigner | Thu, 07/20/2017 - 16:00

Did you really compile LIGGGHTS with VTK support?

If you are not sure, change the dump style from custom/vtk to custom (and the filename, e.g. post/dump_*.particles )