Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2006
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2006

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Performance--Dual Core

  • To: mathgroup at smc.vnet.net
  • Subject: [mg70123] Re: [mg70089] Performance--Dual Core
  • From: "Christoph Lhotka" <lhotka at astro.univie.ac.at>
  • Date: Wed, 4 Oct 2006 05:59:39 -0400 (EDT)

Hi ! 

When using Windows you have to tell the OS the following:

> ----------------------------------------
> Variable Name : OMP_NUM_THREADS
> Variable Value: % NUMBER_OF_PROCESSORS% (e.g. 2)
> ----------------------------------------

(first create a new variable OMP_NUM_THREADS as a System Variable in the
Device Manager, then set the NUMBER_OF_PROCESSORS to 2 (or 3, ...). The values
of OMP_NUM_THREADS should be equal to the value of NUMBER_OF_PROCESSORS...


After doing so, you will see, that Mathematica will use both cores for its
computation...

Christoph


On Tue, 3 Oct 2006 06:16:29 -0400 (EDT)
 oparadis at princeton.edu wrote:
> I have just bought a new system (AMD 64 X2 Dual Core 4200+) thinking it
> would improve computations with mathematica 5.2. I am mainly running
> symbolic computation problems (Solve,Reduce,FullSimplify stuff) involving a
> system of nonlinear equations with domain restrictions over parameters...
> 
> I am puzzled by the fact mathematica seems to be using the CPU resources
> from a single core at the time even though the problem it tries to solve is
> very complicated (takes 1 day approx.). While computing, windows' task
> manager shows "MathKernel" using 50% of CPU and "System Idle Process" using
> the remaining 50%.
> 
> I have 2 questions. First, what's going on ? Is Mathematica really unable
> to use both cores at the same time ? Second, how can one deal with this ?
> Is there a way to force mathematica to somehow split the task between both
> cores ?
> 
> I know some of the previous posts have dealt with similar issues but they
> don't quite seem to answer my specific problem.
> 
> 
> 
> Link to the forum page for this post:
> http://www.mathematica-users.org/webMathematica/wiki/wiki.jsp?pageName=Special:Forum_ViewTopic&pid=14120#p14120
> Posted through http://www.mathematica-users.org [[postId=14120]]
> 
> 

-- Mag. Christoph Lhotka --
University of Vienna / Department of Astronomy
Tuerkenschanzstrasse 17, A-1180 Vienna, Austria
fon. +43 (1) 4277 51841
mail. lhotka at astro.univie.ac.at


  • Prev by Date: RE: Draw approximated normal distribution based on mean, median, percentiles?
  • Next by Date: RE:Dual Core
  • Previous by thread: Re: Performance--Dual Core
  • Next by thread: RE: Re: Performance--Dual Core