From mboxrd@z Thu Jan 1 00:00:00 1970 From: hsggebhardt@googlemail.com (Henry Gebhardt) Date: Sat, 22 Jan 2011 13:00:27 +0100 Subject: dd test discussion (was Re: possible regression?) In-Reply-To: References: Message-ID: <20110122120025.GA32605@bimsstein> To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org On Sat, Jan 22, 2011 at 11:49:43AM +0700, Mulyadi Santosa wrote: > On Fri, Jan 21, 2011 at 20:25, Mag Gam 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 -------------- next part -------------- A non-text attachment was scrubbed... Name: pipespeed.sh Type: application/x-sh Size: 809 bytes Desc: not available Url : http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20110122/4029d980/attachment.sh