From: Greg Smith <greg@2ndQuadrant.com>
To: pgsql-performance@postgresql.org
Subject: Re: Postgres refusing to use >1 core
Date: Mon, 09 May 2011 18:43:52 -0400
Message-ID: <4DC86E28.8020703@2ndQuadrant.com> (raw)
In-Reply-To: <4DC81D56020000250003D438@gw.wicourts.gov>
References: <BANLkTimohiUa6rOYdxYTwqmvSUg2CRYMHg@mail.gmail.com>
<4DC81A3F020000250003D433@gw.wicourts.gov>
<BANLkTimNTLqQgQeyu=FPOn-5x6F4XnVBJA@mail.gmail.com>
<4DC81D56020000250003D438@gw.wicourts.gov>
On 05/09/2011 05:59 PM, Kevin Grittner wrote:
> I'm going to pursue this digression just a little further, because
> it probably will be biting you sooner or later. We make sure to
> configure the BIOS on our database servers to turn off
> hyperthreading. It really can make a big difference in performance.
>
You're using connection pooling quite aggressively though. The sort of
people who do actually benefit from hyperthreading are the ones who
don't, where there's lots of CPU time being burnt up in overhead you
don't see, and that even a virtual HT processor can help handle. I'm
not a big fan of the current hyperthreading implementation, but it's not
nearly as bad as the older ones, and there are situations where it is
useful. I am unsurprised you don't ever see them on your workload
though, you're well tweaked enough to probably be memory or disk limited
much of the time.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books
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To: pgsql-performance@postgresql.org
Cc: greg@2ndQuadrant.com
Subject: Re: Postgres refusing to use >1 core
In-Reply-To: <4DC86E28.8020703@2ndQuadrant.com>
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