How to determine a good value for --load-average using gnu Make?

Question

In Make this flag exists:

-l [load], --load-average[=load] Specifies that no new jobs (commands) should be started if there are others jobs running a

Answer 1

Acceptable load depends on the number of CPU cores. If there is one core, than load average more than 1 is overload. If there are four cores, than load average of more than four is overload.

People often just specify the number of cores using -j switch.

See some empirical numbers here: https://stackoverflow.com/a/17749621/412080