From: Stan Hoeppner <stan@hardwarefreak.com>
To: "Mathias Burén" <mathias.buren@gmail.com>
Cc: Roman Mamedov <rm@romanrm.ru>, CoolCold <coolthecold@gmail.com>,
Linux-RAID <linux-raid@vger.kernel.org>
Subject: Re: Performance question, RAID5
Date: Sun, 30 Jan 2011 14:03:06 -0600 [thread overview]
Message-ID: <4D45C3FA.2040900@hardwarefreak.com> (raw)
In-Reply-To: <AANLkTi=6UnGjDXdrM76-8_iW+1D6MC5fkGB-vhhYxUXu@mail.gmail.com>
Mathias Burén put forth on 1/30/2011 1:41 PM:
> Thanks. New results up for those interested:
> http://stuff.dyndns.org/logs/bonnie_results.html
Three things I notice:
1. You're CPU bound across the board, for all the tests that matter anyway
2. Because of this, your performance spread is less than 5% across the board
meaning any optimizations are useless
3. Is that a 7 Gigabyte chunk size? That's totally unrealistic. It should be
less than 1 MB for almost all workloads.
According to those numbers, you can swap SATA controllers and PCIe bus slot
assignments all day long, but you'll gain nothing without a faster CPU.
Why are you using a 7 Gigabyte chunk size? And if the other OP was correct
about the 768MB stripe cache, that's totally unrealistic as well. And in real
world use, you don't want a high readahead setting. It just wastes buffer cache
memory for no gain (except maybe in some synthetic benchmarks).
--
Stan
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next prev parent reply other threads:[~2011-01-30 20:03 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-29 22:48 Performance question, RAID5 Mathias Burén
2011-01-29 22:53 ` Roman Mamedov
2011-01-29 23:44 ` Mathias Burén
2011-01-29 23:57 ` Roman Mamedov
2011-01-30 0:15 ` Stan Hoeppner
2011-01-30 0:33 ` Mathias Burén
2011-01-30 0:27 ` Mathias Burén
2011-01-30 1:52 ` Keld Jørn Simonsen
2011-01-30 1:54 ` Mathias Burén
2011-01-30 5:56 ` Keld Jørn Simonsen
2011-01-30 12:12 ` Mathias Burén
2011-01-30 19:44 ` Stan Hoeppner
2011-01-30 19:46 ` Mathias Burén
2011-02-01 11:37 ` John Robinson
2011-02-01 13:53 ` Roberto Spadim
2011-02-01 14:02 ` Mathias Burén
2011-02-01 14:32 ` Roberto Spadim
2011-01-29 23:26 ` CoolCold
2011-01-30 0:18 ` Mathias Burén
2011-01-30 4:44 ` Roman Mamedov
2011-01-30 12:09 ` Mathias Burén
2011-01-30 12:15 ` Roman Mamedov
2011-01-30 19:41 ` Mathias Burén
2011-01-30 19:54 ` Roman Mamedov
2011-01-30 19:58 ` Mathias Burén
2011-01-30 20:03 ` Stan Hoeppner [this message]
2011-01-30 21:43 ` Mathias Burén
2011-01-31 3:39 ` Stan Hoeppner
2011-01-31 3:54 ` Roberto Spadim
2011-01-31 8:52 ` Keld Jørn Simonsen
2011-01-31 9:37 ` Mathias Burén
2011-01-31 13:11 ` Keld Jørn Simonsen
2011-01-31 14:43 ` Roberto Spadim
2011-01-31 18:44 ` Keld Jørn Simonsen
2011-01-31 20:42 ` NeilBrown
2011-01-31 21:41 ` Keld Jørn Simonsen
2011-01-31 21:43 ` Roberto Spadim
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