From: Pierre C <lists@peufeu.com>
To: Yeb Havinga <yebhavinga@gmail.com>
To: Greg Smith <greg@2ndquadrant.com>
Cc: Francisco Reyes <lists@stringsutils.com>
Cc: Pgsql performance <pgsql-performance@postgresql.org>
Subject: Re: 10K vs 15k rpm for analytics
Date: Wed, 03 Mar 2010 11:36:55 +0100
Message-ID: <op.u8zmftmjeorkce@localhost> (raw)
In-Reply-To: <4B8E2664.80303@gmail.com>
References: <cone.1267562557.293175.32557.1000@shelca>
<4B8D7A6C.3010304@gmail.com>
<4B8D7D18.9030407@2ndquadrant.com>
<4B8E2664.80303@gmail.com>
>>> With 24 drives it'll probably be the controller that is the limiting
>>> factor of bandwidth. Our HP SAN controller with 28 15K drives delivers
>>> 170MB/s at maximum with raid 0 and about 155MB/s with raid 1+0.
I get about 150-200 MB/s on .... a linux software RAID of 3 cheap Samsung
SATA 1TB drives (which is my home multimedia server)...
IOPS would be of course horrendous, that's RAID-5, but that's not the
point here.
For raw sequential throughput, dumb drives with dumb software raid can be
pretty fast, IF each drive has a dedicated channel (SATA ensures this) and
the controller is on a fast PCIexpress (in my case, chipset SATA
controller).
I don't suggest you use software RAID with cheap consumer drives, just
that any expensive setup that doesn't deliver MUCH more performance that
is useful to you (ie in your case sequential IO) maybe isn't worth the
extra price... There are many bottlenecks...
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: lists@peufeu.com, yebhavinga@gmail.com, greg@2ndquadrant.com, lists@stringsutils.com
Subject: Re: 10K vs 15k rpm for analytics
In-Reply-To: <op.u8zmftmjeorkce@localhost>
* 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