> -----Original Message----- > From: pgsql-performance-owner@xxxxxxxxxxxxxx [mailto:pgsql-performance- > owner@xxxxxxxxxxxxxx] On Behalf Of Scott Marlowe > Sent: Monday, April 11, 2011 1:29 PM > To: Glyn Astill > Cc: Kevin Grittner; Joshua D. Drake; pgsql-performance@xxxxxxxxxxxxxx > Subject: Re: Linux: more cores = less concurrency. > > On Mon, Apr 11, 2011 at 12:23 PM, Glyn Astill <glynastill@xxxxxxxxxxx> > wrote: > > > > > > --- On Mon, 11/4/11, Joshua D. Drake <jd@xxxxxxxxxxxxxxxxx> wrote: > > > >> From: Joshua D. Drake <jd@xxxxxxxxxxxxxxxxx> > >> Subject: Re: Linux: more cores = less concurrency. > >> To: "Kevin Grittner" <Kevin.Grittner@xxxxxxxxxxxx> > >> Cc: pgsql-performance@xxxxxxxxxxxxxx, "Glyn Astill" > <glynastill@xxxxxxxxxxx> > >> Date: Monday, 11 April, 2011, 19:12 > >> On Mon, 11 Apr 2011 13:09:15 -0500, > >> "Kevin Grittner" > >> <Kevin.Grittner@xxxxxxxxxxxx> > >> wrote: > >> > Glyn Astill <glynastill@xxxxxxxxxxx> > >> wrote: > >> > > >> >> The new server uses 4 x 8 core Xeon X7550 CPUs at > >> 2Ghz > >> > > >> > Which has hyperthreading. > >> > > >> >> our current servers are 2 x 4 core Xeon E5320 CPUs > >> at 2Ghz. > >> > > >> > Which doesn't have hyperthreading. > >> > > > > > Yep, off. If you look at the benchmarks I took, HT absoloutely killed > it. > > > >> > PostgreSQL often performs worse with hyperthreading > >> than without. > >> > Have you turned HT off on your new machine? If > >> not, I would start > >> > there. > >> > >> And then make sure you aren't running CFQ. > >> > >> JD > >> > > > > Not running CFQ, running the no-op i/o scheduler. > > Just FYI, in synthetic pgbench type benchmarks, a 48 core AMD Magny > Cours with LSI HW RAID and 34 15k6 Hard drives scales almost linearly > up to 48 or so threads, getting into the 7000+ tps range. With SW > RAID it gets into the 5500 tps range. Just wondering, which LSI card ? Was this 32 drives in Raid 1+0 with a two drive raid 1 for logs or some other config? -M > > -- > Sent via pgsql-performance mailing list (pgsql- > performance@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
