From owner-freebsd-questions Sat Jul 21 13:47:13 2001 Delivered-To: freebsd-questions@freebsd.org Received: from smtprelay2.adelphia.net (smtprelay2.adelphia.net [64.8.25.7]) by hub.freebsd.org (Postfix) with ESMTP id 0EBF137B406 for ; Sat, 21 Jul 2001 13:47:10 -0700 (PDT) (envelope-from ipthomas_77@yahoo.com) Received: from scraemondaemon.my.domain ([24.49.96.3]) by smtprelay2.adelphia.net (Netscape Messaging Server 4.15) with ESMTP id GGUCFB00.TQB; Sat, 21 Jul 2001 16:47:35 -0400 Received: (from ipt@localhost) by scraemondaemon.my.domain (8.11.4/8.11.4) id f6LKj9j06371; Sat, 21 Jul 2001 16:45:09 -0400 (EDT) (envelope-from ipt) Date: Sat, 21 Jul 2001 16:45:09 -0400 From: User & Ian Patrick Thomas To: Bill Moran Cc: freebsd-questions@freebsd.org Subject: Re: How to change UDMA mode on ata drives Message-ID: <20010721164509.A6316@localhost> References: <3B5987B1.C5310BB0@iowna.com> <20010721114445.C5115@localhost> <3B59A707.F4D60AD0@iowna.com> <20010721121247.E5115@localhost> <3B59BAD9.76F2C4C5@iowna.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <3B59BAD9.76F2C4C5@iowna.com>; from wmoran@iowna.com on Sat, Jul 21, 2001 at 01:24:41PM -0400 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 As it was put forth by Bill Moran on Sat, Jul 21, 2001 at 01:24:41PM -0400... > 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 > I'm not sure which one to believe, the FreeBSD man page, or the drive's specs. The man ata says 66 and above for the 80 conductor cable. I'm using a 40 conductor now and dmesg has my drive at 33 UDMA.(It's a Maxtor). As far as how it works, I guess searching online is the best route. Ian > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message