[Haskell-cafe] Significant slow-down in parallel code?

Jamie Morgenstern cantthinkthinkpink at gmail.com
Sun Jan 3 21:50:07 EST 2010


Hello;

 I have a piece of code in which I employ the `par` construct to add some
implicit parallelism
to a theorem prover. However, when running the *same* code with

+RTS -N1
+RTS -N5
+RTS -N10

I see a huge slowdown (a factor of 50 with 5 processes and a factor of 100
for 10 on an 8-core machine).

Very little time is being spent using the garbage collector. Any
suggestions?

Thanks,
-Jamie
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