Hi, > On 7/31/07, Lars Tunkrans <[EMAIL PROTECTED]> wrote: > >> So yes , Thanks to the Stream Benchmark I have now sort of proved >> that the new >> DDR2 memory controller on the AM2 socket Athlon's very nearly >> doubles memory throughput. >> > > BTW, if you are really into getting the best possible Stream number > for your machines, try some extra flags like: -m64 -xopenmp > > * -xopenmp will use both cores of your X2s, so it may be interesting > to see the results... :) > >
Setting OMP_NUM_THREADS to physical processor and core count and comparing results after compiling with -xopenmp is generally an interesting metric to look at as well (the default behaviour is to rely on *OMP_DYNAMIC*, but I'm not sure how that evaluates cores v's threads). > Also, large page and -xprefetch may help, but you will end up spending > lots of time to get an extra few % > > I found -xprefetch -xprefetch_level=3 made the most difference the last time I looked, but as Rayson stated its a lot of experimentation for a small difference. - Fintan > Rayson > > > >> Thanks again >> >> //Lars >> >> >> This message posted from opensolaris.org >> _______________________________________________ >> perf-discuss mailing list >> perf-discuss@opensolaris.org >> >> > > http://gridengine.sunsource.net/ > _______________________________________________ > perf-discuss mailing list > perf-discuss@opensolaris.org > _______________________________________________ perf-discuss mailing list perf-discuss@opensolaris.org
