From: Jonathan Morton <chromi@cyberspace.org>
To: dean gaudet <dean-list-linux-kernel@arctic.org>
Cc: Andre Hedrick <andre@linux-ide.org>,
Linus Torvalds <torvalds@transmeta.com>,
Douglas Gilbert <dougg@torque.net>,
Jeremy Hansen <jeremy@xxedgexx.com>,
<linux-kernel@vger.kernel.org>
Subject: Re: scsi vs ide performance on fsync's
Date: Tue, 6 Mar 2001 13:45:54 +0000 [thread overview]
Message-ID: <l0313030cb6ca98eb60a7@[192.168.239.101]> (raw)
In-Reply-To: <Pine.LNX.4.33.0103060513160.15874-100000@twinlark.arctic.org>
In-Reply-To: <Pine.LNX.4.33.0103060449230.15874-100000@twinlark.arctic.org>
>> i assume you meant to time the xlog.c program? (or did i miss another
>> program on the thread?)
Yes.
>> i've an IBM-DJSA-210 (travelstar 10GB, 5411rpm) which appears to do
>> *something* with the write cache flag -- it gets 0.10s elapsed real time
>> in default config; and gets 2.91s if i do "hdparm -W 0".
>>
>> ditto for an IBM-DTLA-307015 (deskstar 15GB 7200rpm) -- varies from .15s
>> with write-cache to 1.8s without.
>>
>> and an IBM-DTLA-307075 (deskstar 75GB 7200rpm) varies from .03s to 1.67s.
>>
>> of course 1.8s is nowhere near enough time for 200 writes to complete.
>
>hi, not enough sleep, can't do math. 1.67s is exactly the ballpark you'd
>expect for 200 writes to a correctly functioning 7200rpm disk. and the
>travelstar appears to be doing the right thing as well.
I was just about to point that out. :) I ran the program with 2000
packets in order to magnify the difference.
So, it appears that the IBM IDE drives are doing the "right thing" when
write-caching is switched off, but the Seagate drive (at least the one I'm
using) appears not to turn the write-caching off at all. I want to try
this out with some other drives, including a Seagate SCSI drive and a
different Seagate IDE drive (attached to a non-UDMA controller), and
perhaps a couple of older drives which I just happen to have lying around
(particularly a Maxtor and an old TravelStar with very little cache).
That'll have to wait until later, though - university work beckons. :(
--------------------------------------------------------------
from: Jonathan "Chromatix" Morton
mail: chromi@cyberspace.org (not for attachments)
big-mail: chromatix@penguinpowered.com
uni-mail: j.d.morton@lancaster.ac.uk
The key to knowledge is not to rely on people to teach you it.
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next prev parent reply other threads:[~2001-03-06 13:47 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-03-06 5:27 scsi vs ide performance on fsync's Douglas Gilbert
2001-03-06 5:45 ` Linus Torvalds
2001-03-06 7:12 ` Andre Hedrick
2001-03-06 12:09 ` Alan Cox
2001-03-06 18:44 ` Linus Torvalds
2001-03-07 13:48 ` Stephen C. Tweedie
2001-03-07 14:13 ` Jens Axboe
2001-03-12 18:50 ` Andre Hedrick
2001-03-06 13:50 ` Mike Black
2001-03-06 16:02 ` Jeremy Hansen
2001-03-07 18:27 ` Jeremy Hansen
2001-03-07 18:36 ` Linus Torvalds
2001-03-08 11:06 ` Stephen C. Tweedie
2001-03-06 16:57 ` Jonathan Morton
2001-03-06 6:43 ` Jonathan Morton
2001-03-06 13:03 ` dean gaudet
2001-03-06 13:15 ` dean gaudet
2001-03-06 13:45 ` Jonathan Morton [this message]
[not found] <1epyyz1.etswlv1kmicnqM%smurf@noris.de>
2001-03-09 6:59 ` Matthias Urlichs
2001-03-09 11:51 ` Jens Axboe
2001-03-09 14:26 ` Matthias Urlichs
-- strict thread matches above, loose matches on Subject: below --
2001-03-07 12:47 David Balazic
2001-03-06 19:42 David Balazic
2001-03-06 20:37 ` Jens Axboe
2001-03-07 13:51 ` Stephen C. Tweedie
2001-03-07 14:12 ` Jens Axboe
2001-03-07 15:05 ` Stephen C. Tweedie
2001-03-07 18:51 ` Jens Axboe
2001-03-07 19:10 ` Stephen C. Tweedie
2001-03-07 20:15 ` Jens Axboe
2001-03-07 20:56 ` Stephen C. Tweedie
2001-03-07 20:59 ` Jens Axboe
2001-03-08 15:45 ` Chris Mason
2001-03-06 17:14 David Balazic
2001-03-06 17:46 ` Gregory Maxwell
2001-03-06 18:23 ` Jonathan Morton
2001-03-06 23:27 ` Mark Hahn
[not found] <Pine.LNX.4.33L2.0103021033190.6176-200000@srv2.ecropolis.com>
[not found] ` <054201c0a33d$55ee5870$e1de11cc@csihq.com>
2001-03-04 20:10 ` Douglas Gilbert
2001-03-04 21:28 ` Ishikawa
2001-03-06 0:11 ` Douglas Gilbert
2001-03-02 17:42 Jeremy Hansen
2001-03-02 18:39 ` Steve Lord
2001-03-02 19:17 ` Chris Mason
2001-03-02 19:25 ` Steve Lord
2001-03-02 19:27 ` Jeremy Hansen
2001-03-02 19:38 ` Chris Mason
2001-03-02 19:41 ` Steve Lord
2001-03-05 13:23 ` Andi Kleen
2001-03-02 19:25 ` Andre Hedrick
2001-03-03 1:55 ` Dan Hollis
2001-03-02 20:56 ` Linus Torvalds
2001-03-06 2:13 ` Jeremy Hansen
2001-03-06 2:25 ` Linus Torvalds
2001-03-06 3:30 ` Jonathan Morton
2001-03-06 4:05 ` Linus Torvalds
2001-03-06 7:03 ` Andre Hedrick
2001-03-06 8:24 ` Jonathan Morton
2001-03-06 12:22 ` Rik van Riel
2001-03-06 14:08 ` Jonathan Morton
2001-03-07 16:50 ` Pavel Machek
2001-03-06 19:41 ` Andre Hedrick
2001-03-07 5:25 ` Jonathan Morton
2001-03-07 6:58 ` Andre Hedrick
2001-03-09 11:39 ` Jonathan Morton
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