From owner-freebsd-questions Fri Oct 25 9:52:34 2002 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 92CB237B401 for ; Fri, 25 Oct 2002 09:52:33 -0700 (PDT) Received: from q.closedsrc.org (ip233.gte15.rb1.bel.nwlink.com [209.20.244.233]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3AC5E43E3B for ; Fri, 25 Oct 2002 09:52:33 -0700 (PDT) (envelope-from lplist@closedsrc.org) Received: by q.closedsrc.org (Postfix, from userid 1002) id BC91453E8; Fri, 25 Oct 2002 09:51:42 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by q.closedsrc.org (Postfix) with ESMTP id BAE7F53DC; Fri, 25 Oct 2002 09:51:42 -0700 (PDT) Date: Fri, 25 Oct 2002 09:51:42 -0700 (PDT) From: Linh Pham To: lewiz Cc: Steve Warwick , Subject: Re: UDMA limited to 33 - resolution In-Reply-To: <20021023220429.GB1146@lewiz.org> Message-ID: <20021025094838.E58366-100000@q.closedsrc.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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 On 2002-10-23, lewiz scribbled: # Afaik, UDMA100 is only supported if there is just one device on the # channel. Feel free to shoot me if I am incorrect, which is quite # possible. Just double-check by asking Google or something - but I have # a gut feeling this may be the case. You should be able to run two devices at ATA/100 speeds on the same channel provided that you are using a cable within the ATA/100 specs (i.e.: 40-pin/80-conductor, the cable length is about 18" or less, etc.) and that both drives are capable and set to run at ATA/100. Of course, you run into the issue that both drives cannot send data across the channel at once... so you won't gain any performance by doing that. It's just the limitation of ATA (and the reason why Serial ATA only allows one device per host connector, and why higher-end ATA RAID controllers have so many channels and only allow one device per channel). HTH -- Linh Pham lplist@closedsrc.org Webmaster and FreeBSD Geek http://closedsrc.org closedsrc.org Every solution breeds new problems To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message