make -j$n buildworld : use of -j investigated

[Derkjan de Haan]

> With these simple tests, I come to the conclusion that
> "make -j$n buildworld" is best with n = number of CPUs.
> Does that make sense?

Yes, I believe this makes sense. The recommendations made in the handbook
(n >= 4) date back from the time when IO was the bottleneck in the
compilation process i.e. one needed to run multiple build processes in
parallel just to keep the cpu busy. Today this is no longer true, so it's
optimal to use n = number of CPUs. Not sure about Intel cpus with HT
enabled though...


regards,

Derkjan