Subject: Re: sysbench and ubench benchmarks
To: Chris Wareham <chriswareham@chriswareham.demon.co.uk>
From: Bill Stouder-Studenmund <wrstuden@netbsd.org>
List: current-users
Date: 05/04/2007 12:40:32
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On Wed, May 02, 2007 at 07:16:28PM +0100, Chris Wareham wrote:
>=20
> That's one seriously screwed up benchmark test. Firstly, the author
> claims that only companies like Yahoo! bother to tune the OS or database
> engine - sorry, but every company I've worked at employs sysadmins and
> DBA's to do just that. Then he uses a laptop for the OpenBSD and Nexenta
> test runs rather than the desktop machine used for the other systems.
> Not exactly the hardware I'd run a production database server on. Then
> there's the claim that "disk performance depends on how close the
> partition is to the start sector of the disk" - I'm no hardware guru,
> but I was under the impression that modern hard drives had multiple
> platters for starters. Judging by the comment about wanting to test
He's actually right on this one. Disk performance rate does vary as you
move across the disk. It's been a while since I checked, but last time I
looked (1999 to be honest), I saw a 20% variation. For the disk I looked
at, lower sector numbers were faster.
Made life interesting as I was trying to benchmark something that added a=
=20
1% performance penalty. ;-)
I won't bore you with a discussion on why this can be happening, but it=20
certainly can. :-)
Take care,
Bill
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