Date: Mon, 12 Jun 2006 20:29:33 -0400
From: Bill Moran <wmoran@collaborativefusion.com>
To: Anthony Presley <anthony@resolution.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: 64-bit vs 32-bit performance ... backwards?
Message-Id: <20060612202933.4d4221b0.wmoran@collaborativefusion.com>
In-Reply-To: <1150151282.14661.42.camel@tigger>
References: <1150151282.14661.42.camel@tigger>
Organization: Collaborative Fusion
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Anthony Presley <anthony@resolution.com> wrote:

> Hi all!
> 
> I had an interesting discussion today w/ an Enterprise DB developer and
> sales person, and was told, twice, that the 64-bit linux version of
> Enterprise DB (which is based on the 64-bit version of PostgreSQL 8.1)
> is SIGNIFICANTLY SLOWER than the 32-bit version.  Since the guys of EDB
> are PostgreSQL ..... has anyone seen that the 64-bit is slower than the
> 32-bit version?
> 
> I was told that the added 32-bits puts a "strain" and extra "overhead"
> on the processor / etc.... which actually slows down the pointers and
> necessary back-end "stuff" on the database.
> 
> I'm curious if anyone can back this up .... or debunk it.  It's about
> the polar opposite of everything I've heard from every other database
> vendor for the past several years, and would be quite an eye-opener for
> me.

We did some tests on with identical hardware in both EMT64 and ia32 mode.
(Dell 2850, if you're curious)  This was PostgreSQL 8.1 running on
FreeBSD 6.

We found 64 bit to be ~5% slower than 32 bit mode in the (very) limited
tests that we did.  We pulled the plug before doing any extensive
testing, because it just didn't seem as if it was going to be worth it.

-- 
Bill Moran

I already know the ending it's the part that makes your face implode.
I don't know what makes your face implode, but that's the way the movie ends.

	TMBG