From: William Yu <wyu@talisys.com>
To: pgsql-performance@postgresql.org
Subject: Re: What's the best hardver for PostgreSQL 8.1?
Date: Wed, 21 Dec 2005 15:57:56 -0800
Message-ID: <docq5v$24ea$1@news.hub.org> (raw)
In-Reply-To: <200512201950.47671.caseroj@comcast.net>
References: <43A84D03.7090002@ritek.hu>
<D198BAC4-CDC9-494A-A2DA-B05ED585493D@khera.org>
<200512201950.47671.caseroj@comcast.net>
Juan Casero wrote:
> Can you elaborate on the reasons the opteron is better than the Xeon when it
> comes to disk io? I have a PostgreSQL 7.4.8 box running a DSS. One of our
Opterons have 64-bit IOMMU -- Xeons don't. That means in 64-bit mode,
transfers to > 4GB, the OS must allocated the memory < 4GB, DMA to that
block and then the CPU must do extra work in copying the memory to >
4GB. Versus on the Opteron, it's done by the IO adaptor using DMA in the
background.
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: wyu@talisys.com
Subject: Re: What's the best hardver for PostgreSQL 8.1?
In-Reply-To: <docq5v$24ea$1@news.hub.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox