> Is there any problem having that setting active (removing the comment
> marker) for a machine having a single CPU? I.e. can I just activate it
> for all users regardless of CPU configuration or do I need to have a
> smarter setup detecting this and activating/deactivating it accordingly.
>

My understanding is that there is NO DIFFERENCE between explicitly
setting it to 1 and letting the default of 1 take effect at this point
in time. (If a future version of Firebird is released with a
different default setting you may have to update your firebird.conf
files to take advantage of new capabilities if you "force" a specific
setting now instead of just leaving it at default...)

However; If you manage all these servers yourself AND know they have
multiple processors and know what other services are running on them
that may benefit from setting cpu-affinity you may want to try
"balancing" the cpu affinity of these various processes between the
available processors...

(For example: if each of your severs has a Firebird server AND a Web
server running on it you may want to set it so the database work is
done by one processor and the web server work is done by the other
processor, etc...)