From owner-freebsd-stable Fri May 5 11:15:50 2000 Delivered-To: freebsd-stable@freebsd.org Received: from sabre.velocet.net (sabre.velocet.net [198.96.118.66]) by hub.freebsd.org (Postfix) with ESMTP id 5C04A37BBB2 for ; Fri, 5 May 2000 11:15:47 -0700 (PDT) (envelope-from dgilbert@office.tor.velocet.net) Received: from office.tor.velocet.net (trooper.velocet.net [216.126.82.226]) by sabre.velocet.net (Postfix) with ESMTP id 82290138029 for ; Fri, 5 May 2000 14:14:29 -0400 (EDT) Received: (from dgilbert@localhost) by office.tor.velocet.net (8.9.3/8.9.3) id OAA21868; Fri, 5 May 2000 14:14:33 -0400 (EDT) (envelope-from dgilbert) From: David Gilbert MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <14611.3976.69627.957673@trooper.velocet.net> Date: Fri, 5 May 2000 14:14:32 -0400 (EDT) To: Freebsd-stable@freebsd.org Subject: Re: How good is AMI MegaRAID support? X-Mailer: VM 6.75 under 20.4 "Emerald" XEmacs Lucid Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In my testing, I had 8x 18G LVD Quantum drives. With the same batch of drives, Vinum would deliver 35M/s reads and the AMI MegaRAID 1400 would deliver 14M/s reads. We're talking about a straight bonnie test, writing 5G files. The machine in question had 768M of RAM and the AMI 1400 had 64M of onboard (battery backed up) cache and was a PIII/450. I got the same results with both the Adaptec 2940U2W and the TekRAM-590F controllers. The battery-backed-up or not nature of the hardware RAID is immeterial to the "quality" of the system, BTW. The batter is neaded with the hardware solution because the PC doesn't know if the data has been written or not. In the Vinum case, the system knows what's been written and what's not ... (Then you have to start arguing about soft updates and other things --- it gets complicated... but done right you can have a few hundred megs of cache rather than 64) Dave. -- ============================================================================ |David Gilbert, Velocet Communications. | Two things can only be | |Mail: dgilbert@velocet.net | equal if and only if they | |http://www.velocet.net/~dgilbert | are precisely opposite. | =========================================================GLO================ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message