From owner-freebsd-questions Fri Oct 25 10:19:33 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 B2CAC37B401 for ; Fri, 25 Oct 2002 10:19:31 -0700 (PDT) Received: from sage-one.net (adsl-65-71-135-137.dsl.crchtx.swbell.net [65.71.135.137]) by mx1.FreeBSD.org (Postfix) with ESMTP id DAF4E43E65 for ; Fri, 25 Oct 2002 10:19:29 -0700 (PDT) (envelope-from jackstone@sage-one.net) Received: from sagea (sagea [192.168.0.3]) by sage-one.net (8.11.6/8.11.6) with SMTP id g9PHJDb15151; Fri, 25 Oct 2002 12:19:13 -0500 (CDT) (envelope-from jackstone@sage-one.net) Message-Id: <3.0.5.32.20021025121912.01b1e400@mail.sage-one.net> X-Sender: jackstone@mail.sage-one.net X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.5 (32) Date: Fri, 25 Oct 2002 12:19:12 -0500 To: Linh Pham , Kevin Stevens From: "Jack L. Stone" Subject: Re: UDMA limited to 33 - resolution Cc: lewiz , Steve Warwick , In-Reply-To: <20021025094521.B58366-100000@q.closedsrc.org> References: <20021023161917.H11289-100000@babelfish.pursued-with.net> 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 At 09:47 AM 10.25.2002 -0700, Linh Pham wrote: >On 2002-10-23, Kevin Stevens scribbled: > ># However, it *is* correct that all devices on a UDMA channel must support ># UDMA, so yes, the above is a problem. I don't recall if all devices must ># also be the same UDMA speed (66/100/133) or not, bbelieve that is true ># too. This is not a BSD issue, it is part of the UDMA spec. > >IIRC- > >The channel will run at the speed of the slowest device, meaning that if >you have a drive that is capable of ATA/66 and a drive capable of ATA/33 >on the same channel, then the channel will run at ATA/33. > >If you have a drive at ATA/100 and a drive that is only capable of PIO4, >then the speed of the channel will be knocked down to either PIO4 or >ATA/33 (the latter will only occur if the PIO4 drive is also capable to >running at ATA/33, just without DMA). > >-- > >Linh Pham lplist@closedsrc.org Well, then what does the jumper settings on modern drives for "Master with non-ATA compatible sleave" mean in regard to the above speed limits...??? Best regards, Jack L. Stone, Administrator SageOne Net http://www.sage-one.net jackstone@sage-one.net To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message