From owner-freebsd-alpha@FreeBSD.ORG Wed Apr 16 09:57:23 2003 Return-Path: Delivered-To: freebsd-alpha@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 10C6A37B401 for ; Wed, 16 Apr 2003 09:57:22 -0700 (PDT) Received: from trillian.santala.org (ip212-226-173-33.adsl.kpnqwest.fi [212.226.173.33]) by mx1.FreeBSD.org (Postfix) with SMTP id CD6A743F85 for ; Wed, 16 Apr 2003 09:57:20 -0700 (PDT) (envelope-from jake@iki.fi) Received: (qmail 46865 invoked by uid 11053); 16 Apr 2003 16:57:19 -0000 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 16 Apr 2003 16:57:19 -0000 Date: Wed, 16 Apr 2003 19:57:19 +0300 (EEST) From: Jarkko Santala X-X-Sender: jake@trillian.santala.org To: Andrew Gallatin In-Reply-To: <16029.20850.720877.563791@grasshopper.cs.duke.edu> Message-ID: <20030416195422.S316@trillian.santala.org> References: <16029.20850.720877.563791@grasshopper.cs.duke.edu> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: freebsd-alpha@freebsd.org Subject: Re: problem with UDMA mode on XP1000 X-BeenThere: freebsd-alpha@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Porting FreeBSD to the Alpha List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Apr 2003 16:57:23 -0000 On Wed, 16 Apr 2003, Andrew Gallatin wrote: > Jarkko Santala writes: > > On Tue, 15 Apr 2003, Jameel Akari wrote: > > > > > I had the same sort of problem in an Alpha PC164, but in the end > > > the onboard IDE was so terrible and Tru64 refused to run a hard disk on > > > it, so I bought an ISP1040 and went SCSI, and it's been solid. > > > > Well, I don't think it's that terrible: > > > > dd if=/dev/zero of=foo bs=1m count=100: > > ad0: 104857600 bytes transferred in 6.863760 secs (15276991 bytes/sec) > > da0: 104857600 bytes transferred in 8.200968 secs (12786003 bytes/sec) > > > > atapci0: port 0x10180-0x1018f irq 5 at device 11.0 on pci0 > > ad0: 117246MB [238216/16/63] at ata0-master WDMA2 > > FWIW, WDMA2 is not safe as there is no CRC checking. I've seen > corrupted (random, infrequent single bit errors) files when running a > PC164LX with an ata drive in WDMA2 mode. The higher modes (UDMA33 ..) > get you CRC checking. As soon as we noticed the corruption, we moved > the box to SCSI. I suppose no checking explains the performance. ;) But good to know anyway. Any reason why it gets enabled by default if its not safe? -jake -- Jarkko Santala http://www.iki.fi/~jake/ System Administrator 2001:670:83:f08::/64