From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263732AbTKAJPN (ORCPT ); Sat, 1 Nov 2003 04:15:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263734AbTKAJPN (ORCPT ); Sat, 1 Nov 2003 04:15:13 -0500 Received: from ncc1701.cistron.net ([62.216.30.38]:7108 "EHLO ncc1701.cistron.net") by vger.kernel.org with ESMTP id S263732AbTKAJPE (ORCPT ); Sat, 1 Nov 2003 04:15:04 -0500 From: age Subject: Re: READAHEAD Date: Sat, 01 Nov 2003 10:15:28 +0100 Organization: Cistron Message-ID: References: <20031030134407.0c97c86e.akpm@osdl.org> <3FA25377.3050207@cistron.nl> <20031031012846.48fa233c.akpm@osdl.org> <20031031012946.3adedc14.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ncc1701.cistron.net 1067678102 818 62.216.17.166 (1 Nov 2003 09:15:02 GMT) X-Complaints-To: abuse@cistron.nl X-Accept-Language: en To: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > Andrew Morton wrote: > >>Please, just use time, cat, dd, etc. >> >> mount /dev/xxx /mnt/yyy >> dd if=/dev/zero of=/mnt/yyy/x bs=1M count=1024 >> umount /dev/xxx >> mount /dev/xxx /mnt/yyy >> time cat /mnt/yyy/x > /dev/null > > > And you can do the same against /dev/hdaN if you have a scratch > partition; that would be interesting. Hi Andrew, Here are the new test results. hdparm -a0 Timing buffered disk reads: 52 MB in 3.07 seconds = 16.94 MB/sec wuuk:~# dd if=/dev/zero of=/home/test/test bs=1M count=34000 34000+0 records in 34000+0 records out 35651584000 bytes transferred in 922.018299 seconds (38666894 bytes/sec) wuuk:~# time cat /home/test/test > /dev/null real 33m21.785s user 0m19.263s sys 16m31.853s wuuk:~# time rm /home/test/test real 1m35.676s user 0m0.001s sys 0m6.679s hdparm -a16 Timing buffered disk reads: 120 MB in 3.05 seconds = 39.39 MB/sec wuuk:~# dd if=/dev/zero of=/home/test/test bs=1M count=34000 34000+0 records in 34000+0 records out 35651584000 bytes transferred in 920.669609 seconds (38723537 bytes/sec) wuuk:~# time cat /home/test/test > /dev/null real 22m4.180s user 0m18.464s sys 10m42.722s wuuk:~# time rm /home/test/test real 1m35.642s user 0m0.003s sys 0m6.635s hdparm -a256 Timing buffered disk reads: 134 MB in 3.00 seconds = 44.61 MB/sec wuuk:~# dd if=/dev/zero of=/home/test/test bs=1M count=34000 34000+0 records in 34000+0 records out 35651584000 bytes transferred in 920.412114 seconds (38734371 bytes/sec) wuuk:~# time cat /home/test/test > /dev/null real 13m24.228s user 0m10.306s sys 3m3.256s wuuk:~# time rm /home/test/test real 1m35.900s user 0m0.002s sys 0m6.695s hdparm -a4096 Timing buffered disk reads: 168 MB in 3.01 seconds = 55.82 MB/sec wuuk:~# dd if=/dev/zero of=/home/test/test bs=1M count=34000 34000+0 records in 34000+0 records out 35651584000 bytes transferred in 920.198902 seconds (38743346 bytes/sec) wuuk:~# time cat /home/test/test > /dev/null real 15m25.848s user 0m10.716s sys 3m5.103s wuuk:~# time rm /home/test/test real 1m36.205s user 0m0.003s sys 0m6.743s I think you were right :-) groetjes, Age Huisman