C optimization tests - almabench results

[Jim Wilson]

Uros Bizjak wrote:
> I don't think that 15% faster clock can produce such a difference...

Comparing benchmark results on two different machines is tricky.  There 
are lots of different variables that may be affecting the results.
1) different linux distros
2) different kernel versions
3) different glibc versions
4) different memory architectures
5) different main memory sizes and speeds
6) different disk speeds
7) different processors

The last one in particular may be an issue.  You seem to be assuming 
that all Pentium4s are the same, but they aren't.  There are different 
kinds of Pentium4s with different instruction sets and different 
performance profiles.  For instance, your Pentium4 probably has the 
hyperthreading feature, whereas the other one probably doesn't.  The 
previous post mentioned it was using a "Northwood" Pentium4.  You 
probably have a "Prescott".  There are probably other differences 
between Northwood and Prescott.  If they have different cache sizes, and 
the program fits in the Prescott cache but not the Northwood cache then 
that could give significant performance differences.

It is also possible that one of you made a mistake.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com