From owner-freebsd-hardware Tue Jan 26 13:27:27 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA02757 for freebsd-hardware-outgoing; Tue, 26 Jan 1999 13:27:27 -0800 (PST) (envelope-from owner-freebsd-hardware@FreeBSD.ORG) Received: from frmug.org (frmug-gw.frmug.org [193.56.58.252]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id NAA02741 for ; Tue, 26 Jan 1999 13:27:23 -0800 (PST) (envelope-from roberto@keltia.freenix.fr) Received: (from uucp@localhost) by frmug.org (8.9.1/frmug-2.3/nospam) with UUCP id WAA07535 for freebsd-hardware@FreeBSD.ORG; Tue, 26 Jan 1999 22:27:21 +0100 (CET) (envelope-from roberto@keltia.freenix.fr) Received: by keltia.freenix.fr (Postfix, from userid 101) id 4244F1513; Tue, 26 Jan 1999 22:05:10 +0100 (CET) Date: Tue, 26 Jan 1999 22:05:10 +0100 From: Ollivier Robert To: "freebsd-hardware@freebsd.org" Subject: Re: SCSI-3 vrs. ATA Message-ID: <19990126220510.B77068@keltia.freenix.fr> Mail-Followup-To: "freebsd-hardware@freebsd.org" References: <199901261600.KAA22909@mail.netsys.hn> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95i In-Reply-To: <199901261600.KAA22909@mail.netsys.hn>; from FreeBSD Questions on Tue, Jan 26, 1999 at 10:00:40AM -0500 X-Operating-System: FreeBSD 3.0-CURRENT/ELF ctm#4994 AMD-K6 MMX @ 200 MHz Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org According to FreeBSD Questions: > According to the Quantum Spec Sheet on the Web http://www.quantum. > com/products/hdd/fireball_se/datasheet.html > the speed for the ATA is 33.3MB/s and 20MB/s for the SCSI-3 The drive is not able to deliver data that fast. The best you can have now is around 12 MB/s (maybe a bit more but not much). Don't mistake the _bus_ speed with the _drive_ speed. ATA UDMA is a 33 MB/s bus and that seems to be near an UW drive (40 MB/s) but you won't never get that kind of speed from any drive. If you're using a single drive configuration, take either UDMA or SCSI. The only difference you may see is in CPU cycles consumption. SCSI will probably eat a bit less than ATA. If you begin to have more peripherals, like a CD-ROM or a second or third drive, go for SCSI. The disconnect & tagged commands features of SCSI will give you more performance on concurrent accesses than ATA. -- Ollivier ROBERT -=- FreeBSD: The Power to Serve! -=- roberto@keltia.freenix.fr FreeBSD keltia.freenix.fr 3.0-CURRENT #69: Mon Jan 18 02:02:12 CET 1999 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message