From owner-freebsd-scsi Tue Aug 24 11:36:31 1999 Delivered-To: freebsd-scsi@freebsd.org Received: from implode.root.com (root.com [209.102.106.178]) by hub.freebsd.org (Postfix) with ESMTP id A3AD1150D1 for ; Tue, 24 Aug 1999 11:36:00 -0700 (PDT) (envelope-from dg@implode.root.com) Received: from implode.root.com (localhost [127.0.0.1]) by implode.root.com (8.8.8/8.8.5) with ESMTP id LAA15347; Tue, 24 Aug 1999 11:33:59 -0700 (PDT) Message-Id: <199908241833.LAA15347@implode.root.com> To: Nick Hibma Cc: liudong , freebsd-scsi@FreeBSD.ORG Subject: Re: The I/O is too slow than linux In-reply-to: Your message of "Tue, 24 Aug 1999 12:23:53 +0200." From: David Greenman Reply-To: dg@root.com Date: Tue, 24 Aug 1999 11:33:59 -0700 Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >bash-2.03# time dd if=/dev/da0 of=/dev/null count=128000 >128000+0 records in >128000+0 records out >65536000 bytes transferred in 19.586158 secs (3346037 bytes/sec) > >real 0m19.602s >user 0m0.242s >sys 0m3.602s > >bash-2.03# time dd if=/dev/rda0 of=/dev/null count=1000 bs=64k >1000+0 records in >1000+0 records out >65536000 bytes transferred in 7.724508 secs (8484165 bytes/sec) > >real 0m7.749s >user 0m0.015s >sys 0m0.060s > > >Quite a difference. Linux adapts the blocksize to the read size? Does >their implementation of dd do something funny? As I recall, Linux doesn't have block devices (or is it that it doesn't have character devices?....hmmm). -DG David Greenman Co-founder/Principal Architect, The FreeBSD Project - http://www.freebsd.org Creator of high-performance Internet servers - http://www.terasolutions.com Pave the road of life with opportunities. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message