Hello Andrew,

Tuesday, March 3, 2009, 9:21:42 PM, you wrote:

> I just tried it with GHC 6.10.1. Two capabilities is still slower. (See
> attachments. Compiled with -O2 -threaded.)

i don't think so:

  Total time    4.88s  (  5.14s elapsed)

  Total time    7.08s  (  4.69s elapsed)

so with 1 thread wall clock time is 5 seconds, with 2 thread wall time
is 4.7 seconds

cpu time spent increased with 2 threads - this indicates that you
either use hyperthreaded/SMT-capable cpu or speed is limited by memory
access operations

so, my conclusion - this benchmark limited by memory latencies so it
cannot be efficiently multithreaded


-- 
Best regards,
 Bulat                            mailto:bulat.zigans...@gmail.com

_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

Reply via email to