From: Greg Smith <greg@2ndquadrant.com>
To: Yeb Havinga <yebhavinga@gmail.com>
Cc: Matthew Wakeling <matthew@flymine.org>
Cc: pgsql-performance@postgresql.org
Subject: Re: Testing Sandforce SSD
Date: Mon, 26 Jul 2010 11:34:00 -0400
Message-ID: <4C4DAAE8.3060501@2ndquadrant.com> (raw)
In-Reply-To: <4C4D6396.5020707@gmail.com>
References: <4C4A9452.9070100@gmail.com>
<4C4B1F84.5030306@2ndquadrant.com>
<4C4C83DF.3010703@gmail.com>
<4C4C8CCC.7080406@gmail.com>
<alpine.DEB.2.00.1007261045470.20471@aragorn.flymine.org>
<4C4D6396.5020707@gmail.com>
Yeb Havinga wrote:
> Please remember that particular graphs are from a read/write pgbench
> run on a bigger than RAM database that ran for some time (so with
> checkpoints), on a *single* $435 50GB drive without BBU raid controller.
To get similar *average* performance results you'd need to put about 4
drives and a BBU into a server. The worst-case latency on that solution
is pretty bad though, when a lot of random writes are queued up; I
suspect that's where the SSD will look much better.
By the way: if you want to run a lot more tests in an organized
fashion, that's what http://github.com/gregs1104/pgbench-tools was
written to do. That will spit out graphs by client and by scale showing
how sensitive the test results are to each.
--
Greg Smith 2ndQuadrant US Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com www.2ndQuadrant.us
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To: pgsql-performance@postgresql.org
Cc: greg@2ndquadrant.com, yebhavinga@gmail.com, matthew@flymine.org
Subject: Re: Testing Sandforce SSD
In-Reply-To: <4C4DAAE8.3060501@2ndquadrant.com>
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