Nicolas Calimet <pov### [at] freefr> wrote:
> >   I don't really understand why not. Why in windows it's ok for povray
> > to automatically use all available CPUs but in linux it's not?
>
>  The following points were considered when deciding to not make
> the Linux version able to detect the available number of cpus/cores:
>
> 1) Portability: there is no Linux-specific version per se, but a Unix one
> (for now).  Making the Linux executable detect the number of cores is surely
> possible, but there will be many operating systems for which we won't be able
> to do the same (nor even to test whether the detection does work).  Instead,
> a well-defined, documented behavior for all unix-based systems is IMHO
> preferred.  The default of 2 threads, easily changed at the command-line
> or INI level, is probably good enough for most SMP (including dual-core)
> as well as non-SMP machines available nowadays.
>
> 2) Unix (Linux) machines may generally be used by several people at once:
> resource sharing is a concern that should not be left alone to a single
> application, especially with the upcoming multi-core machines.
>
> 3) Nothing says (yet) that 2 threads per core are always optimal.
>
>  - NC

Not to mention that a forced number of threads would eliminate the possibility
using Load Balancing clusters to cooperate.  Thanks so much for making the
decision you did.

Even under windows and others, it may be useful to have an editable override in
the case of clusters.  Both Windows and Mac OSX have packages to do this.
Perhaps on install it could detect the number of cpus and write it to the
application configuration file or so?

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