From: Luke Lonergan <llonergan@greenplum.com>
To: Steve Atkins <steve@blighty.com>
To: Pgsql-Performance ((E-mail)) <pgsql-performance@postgresql.org>
Subject: Re: 64-bit vs 32-bit performance ... backwards?
Date: Mon, 12 Jun 2006 18:50:27 -0700
Message-ID: <C0B367F3.26F29%llonergan@greenplum.com> (raw)
In-Reply-To: <1BAED8DB-01CE-4D10-A509-91FB4DF1F04D@blighty.com>
Opteron is ~20% faster at executing code in 64-bit mode than 32-bit because
of the extra registers made available with their 64-bit mode:
http://www.tomshardware.com/2003/04/22/duel_of_the_titans/page7.html
Doubling the GPRs from 8 to 16 has generally made a 20%-30% difference in
CPU-bound work:
http://www.tomshardware.com/2003/04/22/duel_of_the_titans/page18.html
If the task is memory bandwidth bound, there should be an advantage to using
less memory for the same task, but if the database is using types that are
the same width for either execution mode, you wouldn't expect a significant
difference just from wider pointer arithmetic.
- Luke
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To: pgsql-performance@postgresql.org
Cc: llonergan@greenplum.com, steve@blighty.com
Subject: Re: 64-bit vs 32-bit performance ... backwards?
In-Reply-To: <C0B367F3.26F29%llonergan@greenplum.com>
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