[Paraview] Paraview and Multicore

[Moreland, Kenneth]

Ah, I see.  It sounds like your data is not balanced.  Many of the "non parallel" file formats will do something stupid when loading data in parallel.  For example, they might load everything on process 0 or load everything everywhere.  (And now that I think about it, the Delaunay filter may have trouble in parallel.)

Try running the "Process Id Scalars" filter on your data.  Do the points look evenly distributed?

-Ken


On 5/13/10 10:17 AM, "Guido Staub" <gstaub at udec.cl> wrote:

Well if I start pvserver by mpirun -np 4 pvserver I have 3 cores running
at almost 100%. Now I connect to the server and start a Delaunay 2D
calculation on one of my datasets. As a result all of the 4 cores are
showing 100%. However I assume that there is only one core doing the
job, because on the one hand calculation is really slow. I have done
similar processing on an other PC (an outdated one) and there is no
significant performance advantage as one would expect.
And on the other hand, running pvserver with e.g. -np 2 results in 100%
for 2 CPUs when starting the Delaunay 2D calc (1 core at 100% when
cpu is idle).

Guido


 Am Thu, 13 May 2010
12:39:43 -0600 schrieb "Moreland, Kenneth" <kmorel at sandia.gov>:

> I am afraid I simply don't understand the question.  You said in (1)
> that you have three cores running at 100%.  Then in (2) you said that
> you only have one core running.  Is it happening when you start the
> client, connect the client to the server, launch the server from the
> client, or something else?  Is something running or is the client
> sitting idle waiting for the user?
>
> -Ken
>
>
> On 5/13/10 8:15 AM, "Guido Staub" <gstaub at udec.cl> wrote:
>
> Thanks Ken, but I have already read this thread, therefore I started
> the client process anyway without taking care of cpu usage for now.
>
> However my second question still keeps me busy. Isn't it possible to
> use all 4 cores?
>
> Guido
>
> Am Thu, 13 May 2010
> 10:29:13 -0600 schrieb "Moreland, Kenneth" <kmorel at sandia.gov>:
>
> > The question about why the pvserver processes are always at 100% CPU
> > comes up frequently on the mailing list (such as
> > http://www.paraview.org/pipermail/paraview/2008-December/010338.html).
> > I've added some information to the Wiki about it to provide an
> > explanation:
> > http://www.paraview.org/Wiki/Setting_up_a_ParaView_Server#Server_processes_always_have_100.25_CPU_usage
> >
> > -Ken
> >
> >
> > On 5/13/10 5:06 AM, "Guido Staub" <gstaub at udec.cl> wrote:
> >
> > Hi all,
> >
> > I have succesfully compiled Paraview with MPI support on my
> > Workstation (Quad Core). I have read that paraview runs serial,
> > pvserver parallel, so I started the server by mpirun -np 4 pvserver
> > and connected through X. Everything seems to work fine.
> >
> > But there are two strange behaviours I have noticed:
> >
> > 1. CPU usage on workstation is almost 100% on three of the four
> > cores although no client is connected (when I type mpirun -np 3
> > pvserver there are 2 out of 4 running at 100%; with -np 2 only 1).
> > I have noticed this using MPICH2 and OpenMPI.
> >
> > 2. When I now start a client process the server uses only one core
> > (-np 4/3/2/1). Why?
> >
> > Does MPI not work on multicore systems as on multiprocessor systems
> > or is this a Paraview issue?
> >
> > Thanks,
> > Guido
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> >
> >    ****      Kenneth Moreland
> >     ***      Sandia National Laboratories
> > ***********
> > *** *** ***  email: kmorel at sandia.gov
> > **  ***  **  phone: (505) 844-8919
> >     ***      web:   http://www.cs.unm.edu/~kmorel
> >
>
>
>
>
>    ****      Kenneth Moreland
>     ***      Sandia National Laboratories
> ***********
> *** *** ***  email: kmorel at sandia.gov
> **  ***  **  phone: (505) 844-8919
>     ***      web:   http://www.cs.unm.edu/~kmorel
>




   ****      Kenneth Moreland
    ***      Sandia National Laboratories
***********
*** *** ***  email: kmorel at sandia.gov
**  ***  **  phone: (505) 844-8919
    ***      web:   http://www.cs.unm.edu/~kmorel

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