From: Tejun Heo <htejun@gmail.com>
To: kenneth johansson <ken@kenjo.org>
Cc: linux-ide@vger.kernel.org
Subject: Re: ahci problems with sata disk.
Date: Mon, 15 Jan 2007 22:50:56 +0900 [thread overview]
Message-ID: <45AB86C0.2020507@gmail.com> (raw)
In-Reply-To: <1168859112.6980.8.camel@duo>
kenneth johansson wrote:
> On Mon, 2007-01-15 at 18:13 +0900, Tejun Heo wrote:
>> kenneth johansson wrote:
>>> I changed my bios setting for SATA from IDE to AHCI.
>>>
>>> This resulted in some "interesting" read throughput.
>>>
>>> plots can be found at http://kenjo.org/~ken/sata/
>>> The plots was done on a live disk so some noise is expected but in the
>>> ahci mode the throughput get stuck at 17 MB way to much.
>> It's probably not an ahci problem but more of NCQ implementation problem
>> in the drive firmware. Please report the result of 'hdparm -I /dev/sdX'
>> and try adjust queue depth and see what happens.
>>
>> http://linux-ata.org/faq.html
>>
>
> It was, when I turn of NCQ with "echo 1
>> /sys/block/sda/device/queue_depth" I get the same performance as when
> the BIOS is set to IDE.
Can you play with queue depth a bit? e.g. Benchmark queue depth of 4, 8
and 16.
> I though that NCQ was intended to increase performance ??
Supposedly.
> also the disk is a Westen Digital raptor and it's probably the most
> benchmarked drive one could get so I was not expecting a problem with
> the drive.
Most benchmarked doesn't make the firmware any better, it seems. The
raptor Alan talked about, reportedly, locks up after hours of NCQ load too.
--
tejun
next prev parent reply other threads:[~2007-01-15 13:51 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-01-14 14:32 ahci problems with sata disk kenneth johansson
2007-01-15 9:13 ` Tejun Heo
2007-01-15 11:05 ` kenneth johansson
2007-01-15 11:36 ` Alan
2007-01-15 13:50 ` Tejun Heo [this message]
2007-01-16 1:43 ` kenneth johansson
2007-01-16 16:44 ` Andrew Lyon
2007-01-16 18:32 ` Mark Lord
2007-01-16 20:20 ` Mark Hahn
2007-01-16 22:10 ` Jeff Garzik
2007-01-16 22:26 ` Eric D. Mudama
2007-01-17 22:03 ` Jens Axboe
2007-01-17 22:03 ` Jens Axboe
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