From owner-freebsd-scsi Wed Feb 18 15:52:44 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA14868 for freebsd-scsi-outgoing; Wed, 18 Feb 1998 15:52:44 -0800 (PST) (envelope-from owner-freebsd-scsi@FreeBSD.ORG) Received: from sendero.simon-shapiro.org (sendero-fxp0.Simon-Shapiro.ORG [206.190.148.34]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id PAA14854 for ; Wed, 18 Feb 1998 15:52:38 -0800 (PST) (envelope-from shimon@sendero-fxp0.simon-shapiro.org) Received: (qmail 7813 invoked by uid 1000); 18 Feb 1998 23:57:55 -0000 Message-ID: X-Mailer: XFMail 1.3-alpha-020998 [p0] on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: Date: Wed, 18 Feb 1998 15:57:55 -0800 (PST) Reply-To: shimon@simon-shapiro.org Organization: The Simon Shapiro Foundation From: Simon Shapiro To: Tom Subject: Re: very slow scsi performance Cc: Wee Teck Ng , freebsd-scsi@FreeBSD.ORG, "Justin T.Gibbs" Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On 18-Feb-98 Tom wrote: > > On Wed, 18 Feb 1998, Justin T. Gibbs wrote: > >> The problems that have been reported against many IBM drives stem from >> the fact that the DQUE bit is set on many OEM models. The current SCSI > ... >> drives are behaving completely within the bounds of the SCSI spec. CAM >> handles this "problem" by honoring the DQUE bit assuming that the user >> knows what they are doing. > > Wait a second... that means that those drives don't support tags at > all? > Now I'm sure that I don't want IBM drives. AFAIK, the DPT firmware handles the IBMs fine. Another DPT advantage (from my point of view); Linking and tagging is done by the firmware. The formware is written by people who have access to a bit more hardware and testing environments than we do. The DPT driver does not attempt tagging. No need to. ---------- Sincerely Yours, Simon Shapiro Shimon@Simon-Shapiro.ORG Voice: 503.799.2313 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message