[SciPy-user] Scipy/Numeric slow under Debian?

Greg Novak novak at ucolick.org
Fri Aug 19 01:56:12 CDT 2005

I recently had trouble getting Scipy to work under Fedora 4, and this 
drove me to try Debian.  Now, apt-get python-scipy gets me going just 
fine, but it seems rather... slow.  Code seems to run about a factor of 10 
slower than when I had Scipy running under Fedora 3.

I'm using Debian stable on a dual Intel Xeon 2.8 Ghz.  The version of 
scipy that I got when I installed through apt was 0.3.2.  The slow code is 
heavy on Numeric calls like argsort and cumsum, without much linear 
algebra.  It seems to me that the culprit could be:
1) Compiler optimization
2) instruction set (i386 vs. i686)
3) kernel version (2.4 vs 2.6)
4) Some obscure hardware problem, like Debian isn't using some fancy 
memory-bandwidth enhancing feature that Fedora did (pure conjecture).

All of the above seem unlikely to account for a factor of 10 speed 
difference.  Any insight about what's going on would be much 


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