Re: Postgres 8.4 memory related parameters - Mailing list pgsql-performance

From Shaun Thomas
Subject Re: Postgres 8.4 memory related parameters
Date
Msg-id 4E3B13E8.7050002@peak6.com
Whole thread Raw
In response to Re: Postgres 8.4 memory related parameters  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Responses Re: Postgres 8.4 memory related parameters  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
List pgsql-performance
On 08/04/2011 04:36 PM, Kevin Grittner wrote:

> Anyway, I'm always willing to take advantage of the benchmarking
> work of others, so I'm very curious about where performance topped
> out for you with HT enabled, and whether disk waits were part of the
> mix.

Hah. Well, it peaked at 2x physical cores, where it ended up being 60%
faster than true cores. It started to fall after that, until I hit 64
concurrent connections and it dropped down to 36% faster. I should also
note that this is with core turbo enabled and performance mode BIOS
settings so it never goes into power saving mode. Without those, our
results were inconsistent, with variance of up to 40% per run, on top of
40% worse performance at concurrency past 2x core count.

I tested along a scale from 1 to 64 concurrent connections at a scale of
100 so it would fit in memory. I was trying to test some new X5675s
cores against our old E7450s. The scary part was that a dual X5675 ended
up being 2.5x faster than a quad E7450 at 24-user concurrency. It's
unreal. It's a great way to save on per-core licensing fees.

We're also on an 8.2 database. We're upgrading soon, I promise. :)

--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
sthomas@peak6.com

______________________________________________

See  http://www.peak6.com/email_disclaimer.php
for terms and conditions related to this email

pgsql-performance by date:

Previous
From: "Kevin Grittner"
Date:
Subject: Re: Postgres 8.4 memory related parameters
Next
From: "Kevin Grittner"
Date:
Subject: Re: Postgres 8.4 memory related parameters