Date: Sat, 14 Aug 2010 11:06:58 +0800 From: TJ Varghese <tj@tjvarghese.com> To: Kevin Oberman <oberman@es.net> Cc: Roland Smith <rsmith@xs4all.nl>, stable@freebsd.org Subject: Re: Inconsistent IO performance Message-ID: <AANLkTikkHfwHZAWA35iAG83Pxp4nv2cjhOUd5wMVxsXb@mail.gmail.com> In-Reply-To: <20100814021235.A12771CC3A@ptavv.es.net> References: <20100813213205.GB29150@slackbox.erewhon.net> <20100814021235.A12771CC3A@ptavv.es.net>
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> > > Maybe there is a hardware component here? Are both disks on the same > > controller? Or if not are both controllers using the same interrupt line? > > No. Each is on its one controller and is the only disk on that > controller. > > > You should have a look at 'systat -vmstat' with dd running in the > > background. That might give a clue as to where the bottleneck is. > > > You're using a laptop with 2 HDDs, so does that mean you're using the Ultrabay for the 2nd HDD? Perhaps anything connected to that drops down to ATA33 (pure speculation on my part) since it was designed for optical drives ...dmesg/atacontrol logs would be useful here. You may want to try dd with the of=/dev/null instead to remove the 2nd variable and benchmark solely the read speed of the 1st hdd. regards, TJ
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