> I figured the last time there was no advantage of running 4 verses 2 at a time
> in that it was taking twice as long to run 4 as compared to running 2 then 2
> more ... But like I said I want to get some more figures ...
This is expected behavior ... you are losing a lot of time doing "context switching" which is by far the most "expensive" operation performed by the operating system. This is one of the reasons that "threads" were invented as they are less expensive to perform than a full context switch (change of active process) because the "threads" share the same process context.
You see the same when you run multiple instances of, say, SETI@Home Classic on a single CPU system (neither logical or physical multiple CPUs).
> I figured the last time
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> I figured the last time there was no advantage of running 4 verses 2 at a time
> in that it was taking twice as long to run 4 as compared to running 2 then 2
> more ... But like I said I want to get some more figures ...
This is expected behavior ... you are losing a lot of time doing "context switching" which is by far the most "expensive" operation performed by the operating system. This is one of the reasons that "threads" were invented as they are less expensive to perform than a full context switch (change of active process) because the "threads" share the same process context.
You see the same when you run multiple instances of, say, SETI@Home Classic on a single CPU system (neither logical or physical multiple CPUs).