From owner-freebsd-scsi Wed Sep 18 15:31:58 1996 Return-Path: owner-freebsd-scsi Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id PAA00734 for freebsd-scsi-outgoing; Wed, 18 Sep 1996 15:31:58 -0700 (PDT) Received: from dyson.iquest.net (dyson.iquest.net [198.70.144.127]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id PAA00572; Wed, 18 Sep 1996 15:31:31 -0700 (PDT) Received: (from root@localhost) by dyson.iquest.net (8.7.5/8.6.9) id RAA01314; Wed, 18 Sep 1996 17:31:29 -0500 (EST) From: "John S. Dyson" Message-Id: <199609182231.RAA01314@dyson.iquest.net> Subject: Re: Streamlogic RAID array benchmarks To: freebsd-scsi@freebsd.org Date: Wed, 18 Sep 1996 17:31:29 -0500 (EST) Cc: freebsd-current@freebsd.org, freebsd-isp@freebsd.org In-Reply-To: from "Brian Tao" at Sep 18, 96 06:12:07 pm Reply-To: dyson@freebsd.org X-Mailer: ELM [version 2.4 PL24 ME8] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-scsi@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > > Iozone 2.01 from the packages collection showed a dramatic > difference in favour of the non-RAID drive. It was over twice as fast > as the RAID both in block reads and block writes. I'm a little > suspicious of the read numbers for the single drive... I thought the > ST15150N's maxed out at around 6.5MB/s (at least on narrow > controllers)? I'm seeing over 8MB/s on a single drive. Does the > 2940UW make that much difference even on narrow drives? The test file > size was 128MB. Size is the data block size, Write and Read are in > bytes per second. > If you are running -current (I forgot to check), and since you have 64MBytes, the buffer cache will help even though it is overrun. The buffer cache policy is NOT pure LRU, and you will see the effects of it on a 64MByte system even for a 100MByte benchmark. John