pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  

help / color / mirror / Atom feed
From: Josh Berkus <josh@agliodbs.com>
To: Andres Freund <andres@2ndquadrant.com>
Cc: Bruce Momjian <bruce@momjian.us>
Cc: pgsql-performance@postgresql.org, Mark Kirkwood <mark.kirkwood@catalyst.net.nz>
Cc: Graeme B. Bell <grb@skogoglandskap.no>
Subject: Re: Turn off Hyperthreading! WAS: 60 core performance with 9.3
Date: Mon, 25 Aug 2014 15:13:59 -0700
Message-ID: <53FBB527.9030007@agliodbs.com> (raw)
In-Reply-To: <WM!12468414a2893a5aa6182d55df53428aa09d376e1c00b06b7adacfc72378e3964c2d1bbc4521a25a709fb9d44d394ea8!@asav-2.01.com>
References: <53ACB190.2030206@catalyst.net.nz>
	<WM!d3faee1472c3c4b0fa7a14ce4fee2175ef92f1e0d7e7edb62fe3bcc6fa7e486c99870994a65fa43cc61df990ae549575!@asav-2.01.com>
	<53ECFD75.3060408@agliodbs.com>
	<53ED371D.109@catalyst.net.nz>
	<WM!14a45a34c8080927967621cff2751e173aba58b17a2748a7a628c8fd3be56f3c9596f20e774ed5df15c6863316278466!@asav-2.01.com>
	<53F4F36E.6050003@agliodbs.com>
	<20140821024036.GB26706@momjian.us>
	<WM!a6def31edfeb44a0c2b33db4efa373ee781a1b82f342c0a03c2d35e540e65a0434c32d64b1353526644d086f6706ce42!@asav-3.01.com>
	<53F65E62.3020909@agliodbs.com>
	<20140822140223.GP17406@alap3.anarazel.de>
	<WM!12468414a2893a5aa6182d55df53428aa09d376e1c00b06b7adacfc72378e3964c2d1bbc4521a25a709fb9d44d394ea8!@asav-2.01.com>
List-Unsubscribe:  <mailto:majordomo@postgresql.org?body=unsub%20pgsql-performance>

On 08/22/2014 07:02 AM, Andres Freund wrote:
> On 2014-08-21 14:02:26 -0700, Josh Berkus wrote:
>> On 08/20/2014 07:40 PM, Bruce Momjian wrote:
>>> Not sure how you can make such a blanket statement when so many people
>>> have tested and shown the benefits of hyper-threading.  
>>
>> Actually, I don't know that anyone has posted the benefits of HT.
>> Link?
> 
> There's definitely cases where it can help. But it's highly workload
> *and* hardware dependent.

The only cases I've seen where HT can be beneficial is when you have
large numbers of idle connections.  Then the idle connections can be
"parked" on the HT virtual cores.  However, even in this case I haven't
seen a head-to-head performance comparison.

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com


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



view thread (26+ messages)  latest in thread

Message-ID: <53FBB527.9030007@agliodbs.com>
Permalink:  ../53FBB527.9030007@agliodbs.com/
Also on:    postgresql.org/message-id/53FBB527.9030007@agliodbs.com

 · 

reply
Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-performance@postgresql.org
  Cc: josh@agliodbs.com, andres@2ndquadrant.com, bruce@momjian.us, mark.kirkwood@catalyst.net.nz, grb@skogoglandskap.no
  Subject: Re: Turn off Hyperthreading! WAS: 60 core performance with 9.3
  In-Reply-To: <53FBB527.9030007@agliodbs.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox