In article <40b250b5$1@news.povray.org> , "Ross" <rli### [at] everestkcnet>
wrote:

> They might have no validity from a true benchmarking perspective. However
> they illustrate that compiling the source with a recent compiler can improve
> performance when compared to using the official binary distribution. While
> it is helpfull to understand where exactly the performance gain is comming
> from, to me that is secondary to the fact that there is a performance gain.

This is not the point.  The point is that you cannot take some old version
of a compiler that was set to optimise for one processor and compare it with
a newer version of the same compiler set to optimise for another processor
and conclude anything valid about the effect of the optimisations.  It is
like taking a 1949 Porsche 356 with a top speed of about 140 km/h and
compare it to a 2004 Golf with a top speed of about 160 km/h (smallest
engine) and concluding that a Golf is faster than a Porsche.

As such, only using the same compiler version can possibly be used to
compare optimisation efficiency.  So, looking at the example, and taking any
2004 Porsche, one will quickly find all models have a top speed of over 200
km/h.  So, now only one variable is left (the car type) and as such the
comparison is valid.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

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