From owner-freebsd-current Tue Sep 9 14:48:45 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id OAA08700 for current-outgoing; Tue, 9 Sep 1997 14:48:45 -0700 (PDT) Received: from Octopussy.MI.Uni-Koeln.DE (Octopussy.MI.Uni-Koeln.DE [134.95.166.20]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id OAA08664 for ; Tue, 9 Sep 1997 14:48:36 -0700 (PDT) Received: from x14.mi.uni-koeln.de ([134.95.219.124]) by Octopussy.MI.Uni-Koeln.DE with SMTP id AA09246 (5.67b/IDA-1.5 for ); Tue, 9 Sep 1997 23:48:19 +0200 Received: (from se@localhost) by x14.mi.uni-koeln.de (8.8.7/8.6.9) id XAA01693; Tue, 9 Sep 1997 23:20:03 +0200 (CEST) X-Face: " Date: Tue, 9 Sep 1997 23:20:03 +0200 From: Stefan Esser To: Terry Lambert Cc: Mats Lofkvist , current@FreeBSD.ORG Subject: Re: lousy disk perf. under cpu load (was IDE vs SCSI) References: <199709091225.OAA14331@kairos> <199709091834.LAA28493@usr04.primenet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.74 In-Reply-To: <199709091834.LAA28493@usr04.primenet.com>; from Terry Lambert on Tue, Sep 09, 1997 at 06:34:13PM +0000 Sender: owner-freebsd-current@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Sep 9, Terry Lambert wrote: > > But can lack of tagged command queueing explain the combination of good > > performance unloaded and bad with one or more cpu bound processes? > > Yes, I believe so: swapping. But you need to know for sure if it > is supported in your version, and I'm not the one to ask. Look > at the archives, or wait for Stefan to post. Well, as I always wrote in another message, the NCR driver supports tags for more than 3 years, already ... > > I have no problem with issues with the 810a affecting devices connected > > to it, but is it probable it could affect devices connected to the adaptec? > > No. The problems were specific to the 810a. There is a restriction with the alignment of data moved from memory to memory by the NCR under very specific circumstances (which depend on the chip set and PCI BIOS). But if your chip had that problem and it was not fixed in the driver, the system would fail to boot at all ... Regards, STefan