From: Scott Marlowe <scott.marlowe@gmail.com>
To: James Mansion <james@mansionfamily.plus.com>
Cc: Greg Smith <gsmith@gregsmith.com>
Cc: Scott Carey <scott@richrelevance.com>
Cc: Mark Wong <markwkm@gmail.com>
Cc: pgsql-performance@postgresql.org, "Gabrielle Roth" <gorthx@gmail.com>
Cc: Selena Deckelmann <selenamarie@gmail.com>
Subject: Re: Effects of setting linux block device readahead size
Date: Wed, 10 Sep 2008 23:37:09 -0600
Message-ID: <dcc563d10809102237s2aa1fa09x1df9276282544342@mail.gmail.com> (raw)
In-Reply-To: <48C8AACD.5090702@mansionfamily.plus.com>
References: <70c01d1d0809092353r4ae687a3ycf3d99d43a5680cf@mail.gmail.com>
<Pine.GSO.4.64.0809101023520.15181@westnet.com>
<a1ec7d000809100926w28a4a57dy7c13f2942edc57ff@mail.gmail.com>
<Pine.GSO.4.64.0809101313070.4714@westnet.com>
<48C8AACD.5090702@mansionfamily.plus.com>
On Wed, Sep 10, 2008 at 11:21 PM, James Mansion
<james@mansionfamily.plus.com> wrote:
> Greg Smith wrote:
>>
>> Average seek time: 4ms
>> Seeks/second: 250
>> Data read/seek: 1MB (read-ahead number goes here)
>> Total read bandwidth: 250MB/s
>>
> Most spinning disks now are nearer to 100MB/s streaming. You've talked
> yourself into twice that, random access!
The fastest cheetahs on this page hit 171MB/second:
http://www.seagate.com/www/en-us/products/servers/cheetah/
Are there any drives that have a faster sequential transfer rate out there?
Checked out hitachi's global storage site and they're fastest drive
seems just a tad slower.
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To: pgsql-performance@postgresql.org
Cc: scott.marlowe@gmail.com, james@mansionfamily.plus.com, gsmith@gregsmith.com, scott@richrelevance.com, markwkm@gmail.com, gorthx@gmail.com, selenamarie@gmail.com
Subject: Re: Effects of setting linux block device readahead size
In-Reply-To: <dcc563d10809102237s2aa1fa09x1df9276282544342@mail.gmail.com>
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