3 Mar
2009
3 Mar
'09
6:40 p.m.
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.Ziganshin@gmail.com