From owner-freebsd-chat@FreeBSD.ORG  Tue Jul 27 09:41:51 2010
Return-Path: <owner-freebsd-chat@FreeBSD.ORG>
Delivered-To: freebsd-chat@freebsd.org
Received: by hub.freebsd.org (Postfix, from userid 1233)
	id 26FF11065673; Tue, 27 Jul 2010 09:41:51 +0000 (UTC)
Date: Tue, 27 Jul 2010 09:41:51 +0000
From: Alexander Best <arundel@freebsd.org>
To: freebsd-chat@freebsd.org
Message-ID: <20100727094151.GA68226@freebsd.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.4.2.1i
Subject: ZFS ATA vs. ZFS CAM ATA performance on 8.1
X-BeenThere: freebsd-chat@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Non technical items related to the community
	<freebsd-chat.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-chat>,
	<mailto:freebsd-chat-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-chat>
List-Post: <mailto:freebsd-chat@freebsd.org>
List-Help: <mailto:freebsd-chat-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-chat>,
	<mailto:freebsd-chat-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 27 Jul 2010 09:41:51 -0000

hi there,

i just stumpled upon this article over at phoronix which benchmarks ZFS ATA vs. ZFS CAM ATA on freebsd 8.1 [1].
it seems read performance is really low when CAM ATA is enabled. i remember phoronix being famous for posting stupid benchmarks (RELASE vs. HEAD and such). however their benchmark results in this example seem to be valid.

any comments on that? has performance of ATA CAM increased in HEAD? would a UFS2+S+SUJ ATA vs. UFS2+S+SUJ CAM ATA also show equal results?

cheers.
alex

[1] http://www.phoronix.com/scan.php?page=article&item=freebsd_zfs_cam