yade-users team mailing list archive

[Václav Šmilauer <eudoxos@xxxxxxxx>]

> We are (finally...) starting to benchmark Yade parallel on 3SR cluster 
> with Remi.
> Just a few questions :
> - from triax-perf.py, I understand we are not using the "fast" option 
> by default, right?
> - are we starting the collider at each time step or do we use the 
> version that is only working each N timesteps based on velocity extrema?
By default, fast is not used (unless set differently in the params 
table, if you use yade-multi). With fast, collider runs only every few 
steps (see source of TriaxialTest). Be aware however that due to fast 
motion, tthere is no effect of this in first few hundreds of steps.
> As a preliminary result, Remi said "weird, it using very few cpu". He 
> still investigating this.
http://yade.wikia.com/wiki/Performance_Tuning#openMP

It will run on 16 cores by default. Don't run it on more than 3 or 4 
cores, or your performance will actually go down.

Cheers, V.

PS. I am at a http://www.launchpad.net/esys-particle/ course right now; 
I am sorry to say that, but if you need something high-performance, get 
esys; much better for computing than yade. They can run easily on 512 
cores with almost linear scaling (meaning 10^6 particles in routine 
simulation). Why? They implemented relatively few algorithms 
(constitutive laws, grid-based collision detection, MPI 
parallelization), but they've done them well.