yade-users team mailing list archive

[Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>]

Václav Šmilauer a écrit :
> Bruno: "The time gain with "parallel" option is still very low". What
> speedups you get? For TriaxialTest(fast=True,numberOfGrains=10000), I
> have 48 vs. 28 iter/sec by setting OMP_NUM_THREADS to 4 and 1
> respectively. If you have some ideas for improvements, they will be very
> welcome.
>
>   
Oh!! I still have to try this. I was only looking at this yesterday : 
http://yade.wikia.com/wiki/Triaxial_Test_Parallel

Suggesting a max of 25% speedup. Has it change?

I had a few ideas, like merging geomEngineUnit and physEngineUnit (less 
loops and less sync), or at least don't dispatch interactions when 
i->physics exists . I tried that, it gives 3% speedup just moving 
if(!interaction->interactionPhysics) from the engine unit to the dispatcher.
However, I saw you already merged geom+physics+contact law, so I gave 
up... Is this merged version in the current SVN?
Btw, the scripts/test/triax-perf.py you refer to in this page in not in 
the trunk.

Other questions :
I don't see any parallel command in the triaxialTest or in 
ElasticContactLaw. How can it work?
Do you still have those big cpu time for the collider with 50k spheres? 
I could have a few ideas for this.

Regarding paralelization, we are working on solid-fluid coupling and we 
will use a solver that support parallelization for solving large linear 
systems (an open source library called "taucs", used for sparse system 
in mathematica, matlab, comsol and various good commercial codes). I 
think it will be the good time to start using our multiproc server with 
paralel Yade (I admit I did not really use this server yet...).

> Anton: "Good to have YADE deb-package in repositories.". The
> infrastructure is there, https://launchpad.net/~yade-users/+archive/ppa
> has (one) package, but given the speed how yade evolves and until
> recently, you couldn't practically use it without writing c++ code, it
> didn't make much sense to distribute binaries.
>   
You can still run triaxial tests with various number of grains, 
friction, granulometry, compacity, etc. Not a negligeable thing as the 
triaxial test is the first simulation for more than 50% of the dem users 
I think.

Bruno

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