From: Glyn Astill <glynastill@yahoo.co.uk>
To: Scott Marlowe <scott.marlowe@gmail.com>
Cc: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Cc: Joshua D. Drake <jd@commandprompt.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Linux: more cores = less concurrency.
Date: Mon, 11 Apr 2011 22:08:09 +0100 (BST)
Message-ID: <110350.63036.qm@web26004.mail.ukl.yahoo.com> (raw)
In-Reply-To: <BANLkTi=zS8Lxutk_4n_i=Bgx8B+BuWVPTQ@mail.gmail.com>
--- On Mon, 11/4/11, Scott Marlowe <scott.marlowe@gmail.com> wrote:
> From: Scott Marlowe <scott.marlowe@gmail.com>
> Subject: Re: [PERFORM] Linux: more cores = less concurrency.
> To: "Glyn Astill" <glynastill@yahoo.co.uk>
> Cc: "Kevin Grittner" <Kevin.Grittner@wicourts.gov>, "Joshua D. Drake" <jd@commandprompt.com>, pgsql-performance@postgresql.org
> Date: Monday, 11 April, 2011, 21:52
> On Mon, Apr 11, 2011 at 1:42 PM, Glyn
> Astill <glynastill@yahoo.co.uk>
> wrote:
>
> > A wild guess is something like multiple cores
> contending for cpu cache, cpu affinity, or some kind of
> contention in the kernel, alas a little out of my depth.
> >
> > It's pretty sickening to think I can't get anything
> else out of more than 8 cores.
>
> Have you tried running the memory stream benchmark Greg
> Smith had
> posted here a while back? It'll let you know if
> you're memory is
> bottlenecking. Right now my 48 core machines are the
> king of that
> benchmark with something like 70+Gig a second.
>
No I haven't, but I will first thing tomorow morning. I did run a sysbench memory write test though, if I recall correctly that gave me somewhere just over 3000 Mb/s
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To: pgsql-performance@postgresql.org
Cc: glynastill@yahoo.co.uk, scott.marlowe@gmail.com, Kevin.Grittner@wicourts.gov, jd@commandprompt.com
Subject: Re: Linux: more cores = less concurrency.
In-Reply-To: <110350.63036.qm@web26004.mail.ukl.yahoo.com>
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