From: Glyn Astill <glynastill@yahoo.co.uk>
To: Kevin Grittner <Kevin.Grittner@wicourts.gov>
To: Joshua D. Drake <jd@commandprompt.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Linux: more cores = less concurrency.
Date: Mon, 11 Apr 2011 19:23:50 +0100 (BST)
Message-ID: <895662.51387.qm@web26005.mail.ukl.yahoo.com> (raw)
In-Reply-To: <8b76c51ad6db2e458431ef73bcdd2759@commandprompt.com>
--- On Mon, 11/4/11, Joshua D. Drake <jd@commandprompt.com> wrote:
> From: Joshua D. Drake <jd@commandprompt.com>
> Subject: Re: [PERFORM] Linux: more cores = less concurrency.
> To: "Kevin Grittner" <Kevin.Grittner@wicourts.gov>
> Cc: pgsql-performance@postgresql.org, "Glyn Astill" <glynastill@yahoo.co.uk>
> Date: Monday, 11 April, 2011, 19:12
> On Mon, 11 Apr 2011 13:09:15 -0500,
> "Kevin Grittner"
> <Kevin.Grittner@wicourts.gov>
> wrote:
> > Glyn Astill <glynastill@yahoo.co.uk>
> 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.
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To: pgsql-performance@postgresql.org
Cc: glynastill@yahoo.co.uk, Kevin.Grittner@wicourts.gov, jd@commandprompt.com
Subject: Re: Linux: more cores = less concurrency.
In-Reply-To: <895662.51387.qm@web26005.mail.ukl.yahoo.com>
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