nixnixnix wrote on Fri, 29 January 2010 16:23
Hi,
I have a very strange thing happening. Just over 1 year ago I wrote some multi-threading code that scaled the performance of my calculation linearly with number of virtual cores. However, now that same code performs worse than a single thread.
Using my SVN I have stepped back in time one year and recompiled that code and it performs as I remember it.
My code now is many many times slower and the single threaded version performs better than the multithreaded version.
Generally, this is a sign that either synchronization costs or thread management costs are higher than gains of using multiple cores....
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