From: Tejun Heo <htejun@gmail.com>
To: "François-Julien Marbaud" <fbourget@irisa.fr>
Cc: linux-ide@vger.kernel.org
Subject: Re: Slow perfs with IDE SSD
Date: Thu, 13 Jul 2006 01:21:22 +0900 [thread overview]
Message-ID: <44B52182.3020008@gmail.com> (raw)
In-Reply-To: <loom.20060712T102252-777@post.gmane.org>
François-Julien Marbaud wrote:
> Hi !
>
> I'm doing an internship in a research lab, and we are trying to use a P.ATA SSD
> in order to speed-up a genome computation software.
>
> We got a performance problem, expecially with access time : access time is about
> 800us, and according to the manufacturer it should be about 40us. The bandwith
> is OK.
>
> The SSD is a 2.5' flash hard drive, the slave of the first IDE channel.
>
> We wonder if that could be the because P.ATA driver is not really done for small
> access times, so we got such a poor time. In that case, I guess we would have to
> have a closer look at the driver ...
First of all, try noop elevator.
echo noop > /sys/block/hdx/queue/scheduler
Depending on your workload, adjusting plugging delay/threshold
parameters might help. These are initialized in the kernel source file
block/ll_rw_blk.c::blk_queue_make_request(). q->unplug_thresh and
q->unplug_delay.
--
tejun
next prev parent reply other threads:[~2006-07-12 16:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-12 8:49 Slow perfs with IDE SSD François-Julien Marbaud
2006-07-12 16:21 ` Tejun Heo [this message]
2006-07-12 16:32 ` Tejun Heo
2006-07-13 8:45 ` François-Julien Marbaud
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