--- 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. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
