Date: Mon, 04 Jul 2005 19:13:45 +0100 From: Hugo Silva <adm@celeritystorm.com> To: freebsd-amd64@freebsd.org Subject: Re: better optimization flags for opteron (amd64) Message-ID: <42C97C59.8050609@celeritystorm.com> In-Reply-To: <20050704.141257.104030539.chat95@mac.com> References: <20050704.141257.104030539.chat95@mac.com>
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Hmm, would this be safe to use on all ports? Sometimes speed is nice, but if it breaks stability... NAKATA Maho wrote: >Better optimization flags for Opteron (amd64) > >Recently AMD released a guide >http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/32035.pdf >Compiler Usage Guidelines for 64-Bit Operating Systems on AMD64 Platforms >it has nice flag settings. >recommended flags for opteron/gcc-3.4 is followings: >-pipe -O3 -ffast-math -funroll-all-loops -fpeel-loops -ftracer -funswitch-loops -funit-at-a-time (see p.19 of 32035.pdf) > >and >my benchmark of math/sdpara on Opteron 1.6GHz dual shows: >* scalapack/mpich/blacs is not optimized > 2004.59 real 1979.83 user 9.77 sys > >* scalapack/mpich/blacs is optimized > 1261.85 real 1242.63 user 7.76 sys > >Hope this helps for you. >-- NAKATA, Maho (maho@FreeBSD.org) >_______________________________________________ >freebsd-amd64@freebsd.org mailing list >http://lists.freebsd.org/mailman/listinfo/freebsd-amd64 >To unsubscribe, send any mail to "freebsd-amd64-unsubscribe@freebsd.org" > > >
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