From owner-freebsd-questions Sun Jan 6 16:11: 6 2002 Delivered-To: freebsd-questions@freebsd.org Received: from ptavv.es.net (ptavv.es.net [198.128.4.29]) by hub.freebsd.org (Postfix) with ESMTP id 0456737B41D for ; Sun, 6 Jan 2002 16:10:53 -0800 (PST) Received: from ptavv.es.net (localhost [127.0.0.1]) by ptavv.es.net (Postfix) with ESMTP id B29255D2D; Sun, 6 Jan 2002 16:10:52 -0800 (PST) To: Scott Mitchell Cc: Anthony Atkielski , Cliff Sarginson , FreeBSD Questions Subject: Re: Parts I recommend (formerly "Workstation and server-market") In-reply-to: Your message of "Sun, 06 Jan 2002 12:10:09 GMT." <20020106121009.A338@localhost> Date: Sun, 06 Jan 2002 16:10:52 -0800 From: "Kevin Oberman" Message-Id: <20020107001052.B29255D2D@ptavv.es.net> Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > Date: Sun, 6 Jan 2002 12:10:09 +0000 > From: Scott Mitchell > Sender: owner-freebsd-questions@FreeBSD.ORG > > On Sun, Jan 06, 2002 at 08:29:03AM +0100, Anthony Atkielski wrote: > > Cliff writes: > > > Don't live in the same room as a server with > > > SCSI drives though. They are significantly noisier > > > than ATA ones. > > > > The only difference between them is in the electronics, so I don't know why > > they'd be noisier. > > I'd not be so sure that they're mechanically identical -- IME the failure > rate for ATA drives is much higher than the SCSI ones, despite the fact > that the SCSI server drives do a lot more work than the ATA units in the > workstations. Of course most SCSI drives are going to be running at 10Krpm > or above, while your typical ATA drive does 5400 or 7200rpm, so there's > some extra noise for you right away... I suspect there might be some > mechanical differences between a drive that has to run reliably for years > at 15Krpm and one that's idle half the time at 5400rpm in someone's > desktop. They are sometimes similar and do share many part, but, even on close to "identical" drives, there are differences (or were, the last time I looked into drive manufacturing). First, and probably most significant, is sound level. Most SCSI drives are aimed at the server market and not the office. As a result, there is no sound deadening built into them. While the addition of sound deadening does not effect performance much, it does really impact reliability. It impedes heat transfer and makes the driver run hotter. Other differences include faster (and more robust) positioning motors, different head acceleration profiles (beyond that enforced by the cheaper hardware) to further quiet the drive, and larger spindle motors. In recent times the SSI market has moved to much more differences due to things like faster rotation, but even then, many mechanical components are identical. The cost differential is also growing since ATA drives are built in MUCH larger numbers and targeted toward the low end of the market (desktops). Profit margins are probably MUCH thinner on ATA drives. R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message