Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2007
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2007

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

Search the Archive

Re: FactorInteger slow in V6.0 vs V5.2

  • To: mathgroup at smc.vnet.net
  • Subject: [mg81210] Re: FactorInteger slow in V6.0 vs V5.2
  • From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
  • Date: Sat, 15 Sep 2007 04:19:14 -0400 (EDT)
  • Organization: The Open University, Milton Keynes, UK
  • References: <fcb37e$fba$1@smc.vnet.net>

Mark Fisher wrote:

> In version 5.2 the following runs pretty fast (not more than a couple
> of minutes)
> 
> FactorInteger[2^227-1]
> 
> but quite slow in version 6.0 (I'm not sure how long). Any ideas as to
> why?

On my system (Pentium 4 HT 2.6 MHz 1 Mo Windows XP SP2) version 6.0.1 is 
  about 34 times *slower* than version 5.2 (3556.06 seconds against 
105.688, respectively).

In[1]:=
$Version
Timing[FactorInteger[2^227-1]]

Out[1]=
5.2 for Microsoft Windows (June 20, 2005)

Out[2]=
{105.688 Second,{{26986333437777017,1},{\
7992177738205979626491506950867720953545660121688631,1}}}

In[1]:= $Version
Timing[FactorInteger[2^227 - 1]]

Out[1]= "6.0 for Microsoft Windows (32-bit) (June 19, 2007)"

Out[2]= {3556.06, {{26986333437777017,
    1}, {7992177738205979626491506950867720953545660121688631, 1}}}

Regards,
-- 
Jean-Marc


  • Prev by Date: Re: FactorInteger slow in V6.0 vs V5.2
  • Next by Date: Re: FactorInteger slow in V6.0 vs V5.2
  • Previous by thread: Re: FactorInteger slow in V6.0 vs V5.2
  • Next by thread: Re: FactorInteger slow in V6.0 vs V5.2