Do you use the calibrate command or a batch analysis of matchfiles? The former was shown to be of no value for benchmarks, see here: http://lists.gnu.org/archive/html/bug-gnubg/2009-08/msg00006.html
With calibrate I had the very same effect of high idle times during benchmarks, unless I used at least 8 threads per physical core. I am doing benchmark on a 4 core machine which iterates over #thread (1..6) and cache size (2^1 .. 2^27). Should be posted in say 3 hours, it literally is still running :) Ingo > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On > Behalf Of Louis Zulli > Sent: Thursday, August 06, 2009 3:21 PM > To: Michael Petch > Cc: [email protected] > Subject: [Bug-gnubg] Re: Getting gnubg to use all available cores > > > > On Aug 5, 2009, at 4:02 PM, Michael Petch wrote: > > > I'm unsure how the architecture is deployed and how OS/X > handles the > > physical cores, but it almost sounds like one Physical core is being > > used > > (Using Hyperthreads to run 2 threads simultaneously). I wonder if > > the memory > > is shared across all the cores? A friend of mine was > suggesting that > > people > > may have to wait for Snow Lapard to come out before OS/X properly > > utilizes > > the Nehalem architecture (whetehr that si true or not, I > don't know). > > > > Anyway, as an experiment. If you run 2 copies of Gnubg at the same > > time > > (using multiple threads) do you get 400% CPU usage? > > > > > Hi Mike, > > Sorry for the delay. I just had two copies of gnubg analyze the same > game, using 3 ply analysis. Each instance of gnubg used 200% > CPU. Each > copy was set to use 4 evaluation threads. > > So what's the verdict here? Is Leopard simply not directing threads > correctly? > > Louis > > > > > > _______________________________________________ > Bug-gnubg mailing list > [email protected] http://lists.gnu.org/mailman/listinfo/bug-gnubg _______________________________________________ Bug-gnubg mailing list [email protected] http://lists.gnu.org/mailman/listinfo/bug-gnubg
