Date: Thu, 8 May 2003 13:51:17 -0300 (ADT)
From: The Hermit Hacker <scrappy@postgresql.org>
To: lista@profit-ti.com.br
Cc: pgsql-hackers@postgresql.org
Subject: Re: Hyper-Threading
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Message-ID: <20030508134817.Y728@hub.org>
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I've heard conflicting reports about HyperThreading in general ... by
default, FreeBSD doesn't enable it (it originally did), as ppl were
reporting performance degradation ... I'm using it on our servers, and
haven't noticed any problems ...

As far as PostgreSQL is concerned, how well it takes advantage of it is
alot more dependent, I think, on the OS itself then on the application ...
PostgreSQL is multi-process, but its the OS itself that handles the
schedualing between CPUs, and how those resources are allocated ...

My understanding of HyperThreading is that on a DualCPU box, you end up
with 4 CPUs running at ~67% each, instead of 2 CPUs running at 100% each
... or ~1.5x faster, depending on how well the OS itself handles it ...

On Thu, 8 May 2003 lista@profit-ti.com.br wrote:

> Hi People! 
> As a project manager I decided to migrate the full project from Oracle
> to PostgreSQL.
> 
> We bought a new Intel box to host the database, it is a dual Xeon 2.2
> and I intend to use it with a FreeBSD 4.8  wich support Intel Hyper-
> Threading.
>  
> I Woul like to know if the PostgreSQL 7.3.2 will take advantage from
> Hyper-Threading?
> Best Regards,
>
>
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Marc G. Fournier                   ICQ#7615664               IRC Nick: Scrappy
Systems Administrator @ hub.org
primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org