From owner-freebsd-questions Sat Jul 21 10:24:57 2001 Delivered-To: freebsd-questions@freebsd.org Received: from clmboh1-smtp3.columbus.rr.com (clmboh1-smtp3.columbus.rr.com [65.24.0.112]) by hub.freebsd.org (Postfix) with ESMTP id 9222F37B405 for ; Sat, 21 Jul 2001 10:24:54 -0700 (PDT) (envelope-from wmoran@iowna.com) Received: from iowna.com (dhcp065-024-023-038.columbus.rr.com [65.24.23.38]) by clmboh1-smtp3.columbus.rr.com (8.11.2/8.11.2) with ESMTP id f6LHLHO03071; Sat, 21 Jul 2001 13:21:17 -0400 (EDT) Message-ID: <3B59BAD9.76F2C4C5@iowna.com> Date: Sat, 21 Jul 2001 13:24:41 -0400 From: Bill Moran X-Mailer: Mozilla 4.76 [en] (X11; U; FreeBSD 4.3-STABLE i386) X-Accept-Language: en MIME-Version: 1.0 To: User & Ian Patrick Thomas Cc: freebsd-questions@FreeBSD.ORG Subject: Re: How to change UDMA mode on ata drives References: <3B5987B1.C5310BB0@iowna.com> <20010721114445.C5115@localhost> <3B59A707.F4D60AD0@iowna.com> <20010721121247.E5115@localhost> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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 User & Ian Patrick Thomas wrote: > > As it was put forth by Bill Moran on Sat, Jul 21, 2001 at 12:00:07PM -0400... > > The only options I have through sysctl are hw.atamodes, and hw.ata.ata_dma > > both of which only allow turning DMA on and off. I would like to leave it > > on, but force the controller to use UDMA4 (ata66) instead of UDMA5 (ata100) > > > > Is there a method for this, or is it an on/off proposition? > > I havn't found one that allows you to specify 66 instead of 100. If > you wanted to throttle down to 33 then you could use the 40 cable, but both > 66 and 100 use the 80 cable, correct? The driver uses the maximum > achievable speed. Could it be that the source to the driver needs to be > tweaked? Actually, according to the spec sheets for this drive, you need an 80 pin for anything ata33 or faster. Thus plugging in a 40pin will slow the thing down to 16MB/sec. Not what I want, but if it proves reliable, it will be one step closer to having this problem solved! On a side note ... I'm a little lost with this 80 pin thing. How does an 80 conductor cable with a 40 pin connector on each end do anything more than a 40 conductor cable? Seems a little odd to me. -Bill -- It may be that true happiness is nothing more than the ability to *always* know the right thing to say at the right time, whereas true misery is the state of perpetually saying to oneself, "What I *should* have said was..." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message