From owner-freebsd-hardware Tue Jan 26 21:18:30 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id VAA28139 for freebsd-hardware-outgoing; Tue, 26 Jan 1999 21:18:30 -0800 (PST) (envelope-from owner-freebsd-hardware@FreeBSD.ORG) Received: from panzer.plutotech.com (panzer.plutotech.com [206.168.67.125]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id VAA28134 for ; Tue, 26 Jan 1999 21:18:28 -0800 (PST) (envelope-from ken@panzer.plutotech.com) Received: (from ken@localhost) by panzer.plutotech.com (8.9.2/8.8.5) id WAA48800; Tue, 26 Jan 1999 22:18:13 -0700 (MST) From: "Kenneth D. Merry" Message-Id: <199901270518.WAA48800@panzer.plutotech.com> Subject: Re: SCSI-3 vrs. ATA In-Reply-To: <19990127002442.A78002@keltia.freenix.fr> from Ollivier Robert at "Jan 27, 99 00:24:42 am" To: roberto@keltia.freenix.fr (Ollivier Robert) Date: Tue, 26 Jan 1999 22:18:13 -0700 (MST) Cc: freebsd-hardware@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL28s (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Ollivier Robert wrote... > According to David Webster: > > way get your self a reputable Raid controller and at least three > > 10,000RPM Ultrawide SCSI drives from someone like Seagate in a Raid5 > > Well, we could argue about the 10k rpms drives. Is there so big a > difference with 7200 rpms ones ? It seems to me that 10k are only slightly > faster but they're warmer and noisier. How many 7200 RPM drives can do 18MB/sec? I've got a machine with two 18GB Seagate Cheetah II's in a CCD array. They can do 36MB/sec reads, and 30 or 31MB/sec writes. The third generation Cheetahs look like they'll be even faster. [ NB: the read rate *could* be a little low, since there is one other disk on the chain, and unfortunately the SCA->68pin converters we have seem to force single ended operation. i.e., we're limited to 20MHz Wide instead of 40MHz Wide. ] My IBM Ultrastar 9ZX can do between 13 and 15MB/sec. For a good comparison, go to the Seagate or IBM web sites, and compare their latest-generation 7200 RPM drives with their latest-generation 10000 RPM drives. It looks like for both vendors, their 10K RPM drives are generally about 5MB/sec faster than their 7200RPM drives. Ken -- Kenneth Merry ken@plutotech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message