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Linear algebra performance between 5.0 and 5.2

  • To: mathgroup at smc.vnet.net
  • Subject: [mg61118] Linear algebra performance between 5.0 and 5.2
  • From: Antti Penttilä@smc.vnet.net
  • Date: Tue, 11 Oct 2005 03:20:09 -0400 (EDT)
  • Organization: University of Helsinki
  • Sender: owner-wri-mathgroup at wolfram.com

Hello all,

I updated my Mathematica from 5.0 to 5.2 on a Windows XP, dual Athlon MP 1900+ machine. Then I wanted to see if there are any speed improvements e.g. in linear algebra. With 5.0 i had, for example

n1 = 2000;
c = Table[ Random[], {i, n1}, {j, n1}];
Timing[ Inverse[ c];]

{8. Second,Null}

and processor utilization was almost 100% when calculating.

With 5.2 I have now
n1 = 2000;
c = Table[ Random[], {i, n1}, {j, n1}];
Timing[ Inverse[ c];]

{25.64 Second,Null}

with processor utilization only at 50%, which means that only one processor is calculating. What's the matter with this, how can I utilize both processors automatically?



-- 
   Antti Penttilä       Antti.I.Penttila at helsinki.fi.removethis
     Researcher                     Observatory
tel. +358 50 5240968        00014 University of Helsinki


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