Re: Postgresql slow on XEON 2.4ghz/1gb ram

----- Original Message -----
From: "The Hermit Hacker" <scrappy(at)postgresql(dot)org>
To: "Wilson A. Galafassi Jr." <juniorlist(at)yahoo(dot)com(dot)br>
Cc: <pgsql-admin(at)postgresql(dot)org>
Sent: Wednesday, August 06, 2003 3:10 PM
Subject: Re: [ADMIN] Postgresql slow on XEON 2.4ghz/1gb ram

>
>
>
> On Wed, 6 Aug 2003, Wilson A. Galafassi Jr. wrote:
>
> > Hello.
>
> > I have this problem: i'm running the postgre 7.3 on a windows 2000
> > server with P3 1GHZ DUAL/1gb ram with good performance. For best
> > performance i have change the server for a XEON 2.4/1gb ram and for my
> > suprise the performance decrease 80%. anybody have a similar experience?
> > does exist any special configuration to postgre running on a Xeon
> > processor? Any have any idea to help-me? Excuse-me my bad english.
>
> Don't know how Windows2000 deals with it, but I've noticed "noticeable"
> slowdowns with Xeon+Hyperthreading turned on ...

I would say that you are on the right track with this suggestion.

Hyperthreading in P4/Xeon processors is supposed to emulate multiple processors
but be more efficient by being in one processor.
I can't remember which mag. it was I read now, but real world tests have shown
that it isn't all what its made out to be and that dual processors on most
cases out-performed the so called equivalent P4/Xeon processor.
The other point is, when installing W2K, windows may or may not detect the Xeon
as a multiple processor system and therefore only install the single processor
version of the kernel. So you might want to check that you have multiple
processor version of the kernel installed?
If you have got the multiple processor version installed then the kernel
obviously doesn't handle the Xeon hardware well and you might want to try a
single processor kernel version and see how you get on.

Regards
Donald Fraser.