Re: [gentoo-user] i386 vs amd64

[Rob <europa100@comcast.net>]

Scott Tiret wrote:
> On Thu, 2005-10-20 at 20:07 -0400, Sean wrote:
> 
>>I have a dual opteron here and I am thinking of putting Gentoo on it. I 
>>am trying to decide to go with either the amd64 or i386 version.
>>So I am asking some Gentoo amd64 users, are you happy with the version 
>>or would you have gained more with i386?
>>Do most applications work on amd64 or are there some important ones missing?
> 
> 
> I have been running an x86_64 (amd64) system for a few months now.  The
> only thing I have been missing is a 64bit version of Macromedia
> Shockwave plugin.  Apparently, there is no 64bit version for this
> proprietary software.
> 
> Everything else is fine.  I have all I need on my desktop.  x86_64
> version of Openoffice-bin (rc3) takes a long time to open, but is
> promising.
> 
> Good luck,
> 
I thought the email might be a good place to ask for some ideas:

I don't want to start a 64bit vs 32 bit war, or a Windows versus *nix
war, but it has been my experience so far that the fastest benchmarks
for a highly computation intensive program written in Numeric Python
came on my 3.5Ghz P4 laptop with hyperthreading- on Windows.  Also,
running the same program on an AMD Opteron gave me a slower speed no
matter what OS I was using.  I performed the experiments when the
Opteron was first introduced.  I paid a high price for the fastest chip
I could find- I don't remember the exact speed.  I haven't tried the
test lately though.  Maybe it has gotten much better.

Do not ask me why it happened, I have no idea. But even now, Windows+P4
has consistently been 3x faster in execution time than any Python on 32
bit *nix systems.  The specific program is a Numeric Python port of the
NEC2 EM Simulator program which calculates the Norton-Summerfield ground
coefficients under an antenna.  It makes much use of Complex-64
variables.  I ported it from FORTRAN so I could more easily see how the
program worked.

I am baffled by the behavior.  The only thing I can figure might be
occuring would be that the *nix 64 bit toolchains are much younger than
the 32 bit ones.  But as the 32 bit Numeric Python on Windows is still
3x faster than the *nix equivalents, I have asked Activestate, the
Windows Python provider, if they do anything special when compiling the
code and they say no.  I think they said that they use some ordinary MS
comiler.

Any ideas would help me to put to rest the problem.  I say it is a
problem as I really don't want to boot into Windows XP to run scientific
programs in Numeric Python.

Thanks,

Rob.
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