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From: hsggebhardt@googlemail.com (Henry Gebhardt)
To: kernelnewbies@lists.kernelnewbies.org
Subject: dd test discussion (was Re: possible regression?)
Date: Sat, 22 Jan 2011 13:00:27 +0100	[thread overview]
Message-ID: <20110122120025.GA32605@bimsstein> (raw)
In-Reply-To: <AANLkTi=LZvUg2Auuksq1s5pw00qdgvnO3Mh1AJ8D9vRi@mail.gmail.com>

On Sat, Jan 22, 2011 at 11:49:43AM +0700, Mulyadi Santosa wrote:
> On Fri, Jan 21, 2011 at 20:25, Mag Gam <magawake@gmail.com> wrote:
> > Anyone had a chance to try this? :-)
> 
> $ for a in `seq 1 3`; do \time dd bs=4K count=1M if=/dev/zero of=/dev/null; done

Hm, I also wrote a little script to go through more values of bs.  The
script is attached.  To change what values to use for bs, change the
variables $min, $step, and $max at the beginning of the script, which
are the parameters for "seq".  To get a graph of throughput versus bs,
use it like so:

   $ ./pipespeed.sh > data
   [...]
   $ gnuplot
   plot "data" w l

The highest I get is 8.5 GB/s with bs=22528 on 2.6.37.

How can you get a speed of 30 GB/s?  It seems excessively fast. :)


Greetings,

Henry
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  reply	other threads:[~2011-01-22 12:00 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-22  4:49 dd test discussion (was Re: possible regression?) Mulyadi Santosa
2011-01-22 12:00 ` Henry Gebhardt [this message]
2011-01-22 16:30   ` Mulyadi Santosa
2011-01-22 20:09     ` Henry Gebhardt
2011-01-23  3:25       ` Mulyadi Santosa
2011-01-22 17:41   ` Mulyadi Santosa

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