Solving problems using multiple cores

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dudchenkoav
Posts: 7
Joined: Mon Feb 17, 2020 3:27 pm

Solving problems using multiple cores

Post by dudchenkoav » Thu Jun 18, 2020 3:28 pm

Hello!

I have a problem with static and transient analysis using multiple cores. I prepared a model and permorfed the analysis using a single core. However, I can not tune the model so that all the CPU cores are utilized in analysis.
Could anyone give recomendations or send a link with the instructions on how to prepare the model to run analysis using many cores?

Best Regards,
Aleksandr

STKO Team
Posts: 154
Joined: Tue Oct 29, 2019 8:45 am

Re: Solving problems using multiple cores

Post by STKO Team » Fri Jun 19, 2020 8:43 am

Dear user,

It is pretty straightforward.
In this webinar we explained how to convert a sequential model into a parallel one:
https://youtu.be/m65mJq6Uce8
If you don't want to watch the entire webinar (about 2 hours), the conversion to parallel analysis is performed around 1:38:00.

As you will see in the webinar, the basic steps are:
  • for each AnalysisStep of type "AnalysesCommand":
    • use the parallel numberer (Parallel RCM)
    • use the MUMPS system (the only one that runs in parallel for generic sparse problems... There is also the ParallelSPD, but you should make sure your system is SPD[Symmetric Positive Definite])
    • In case of DisplacementControl, you should change it to ParallelDisplacementControl
  • Partition the mesh in as many partitions as the number of cores you want to use. Don't use to many cores if your model is small, otherwise the parallel overhead will dominate. Let's say that about 1000 elements per core (at least) is fine.
  • In the Analysis Tab, choose the OpenSeesMP solver and run it!
  • When the analysis is done, you will see many MPCO output files (1 per partition). In the post processor you just need to load (OpenDB) one of them, and thanks to their naming convention, STKO will understand that they are all part of 1 analysis, so will open all the others for you.
Let us know if it works

dudchenkoav
Posts: 7
Joined: Mon Feb 17, 2020 3:27 pm

Re: Solving problems using multiple cores

Post by dudchenkoav » Fri Jun 19, 2020 3:00 pm

Dear STKO Team,

thanks a lot for your answer. Yes, it works now.

Best Regards,
Aleksandr

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