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