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From: Chuck Ebbert <76306.1226@compuserve.com>
To: Mens Rullgerd <mru@users.sourceforge.net>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: DMA transfers in 2.5.67
Date: Wed, 16 Apr 2003 05:45:20 -0400	[thread overview]
Message-ID: <200304160548_MC3-1-349F-E844@compuserve.com> (raw)


> Btw, I just noticed that hard disk throughput is much lower with 2.5
> than 2.4.  With 2.4.21-pre5 I get ~40 MB/s, but with 2.5.67 the speed
> drops to 25-30 MB/s.  Everything according to hdparm.  Is it possible
> that DMA is generally slow for some reason?


  I am seeing that too, with IDE hardware.

  And 2.4.20aa1 is even faster:



# mount /ext3_fs
# time dd if=/ext3_fs/100MiB_file of=/dev/null bs=32k



  2.4.20aa1 : 3.3 sec (exactly what I expect to see)
  2.5.66    : 6.6 sec


--
 Chuck

             reply	other threads:[~2003-04-16  9:42 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-04-16  9:45 Chuck Ebbert [this message]
2003-04-16 10:11 ` Andrew Morton
2003-04-16 10:13   ` Andrew Morton
2003-04-16 10:13   ` Måns Rullgård
  -- strict thread matches above, loose matches on Subject: below --
2003-04-18 11:25 Chuck Ebbert
2003-04-15 20:01 Måns Rullgård
2003-04-15 20:31 ` Alan Cox
2003-04-15 21:38   ` Måns Rullgård
2003-04-15 20:48     ` Alan Cox
2003-04-15 22:09       ` Måns Rullgård
2003-04-16  8:36         ` Ivan Kokshaysky
2003-04-16  8:43           ` Måns Rullgård
2003-04-16  8:59             ` Måns Rullgård
2003-04-16  9:30               ` Måns Rullgård
2003-04-16 10:01                 ` Ivan Kokshaysky
2003-04-16 10:11                   ` Måns Rullgård

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