[erlang-questions] multicore performance fine grained concurrency

[David N Murray]

On May 6, Johan Montelius scribed:

>
>
>
> smp 4:4 -> 126 ms
> smp 2:2 -> 143 ms
> smp disabled -> 65 ms
>
> :-(
>

I saw something similar using the Ring benchmark on both AMD (OpenBSD) and
Intel (Vista) dual cores.  Both cores get utilized in the 40-50% range
with smp enabled.  It takes 1/4 the time to run the benchmark with smp
disabled as it does when smp is enabled. Takes advantage of two cores just
fine if you run two OS processes with SMP disabled.  Doesn't do so well
SMP enabled.  The ring benchmark just spawns and sends messages.

smp 2:2 -> 18003 ms
smp disabled -> 4867 ms
2 os processes -> ~5900 ms

hth,
Dave