From owner-freebsd-current Tue Sep 9 12:23:12 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id MAA28852 for current-outgoing; Tue, 9 Sep 1997 12:23:12 -0700 (PDT) Received: from mail.uniserve.com (dns1-van.uniserve.com [204.244.163.48]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id MAA28845 for ; Tue, 9 Sep 1997 12:23:07 -0700 (PDT) Received: from shell.uniserve.com [204.244.210.252] by mail.uniserve.com with smtp (Exim 1.70 #1) id 0x8VvL-0002RP-00; Tue, 9 Sep 1997 12:26:07 -0700 Date: Tue, 9 Sep 1997 12:15:44 -0700 (PDT) From: Tom To: Terry Lambert cc: Mats Lofkvist , current@freebsd.org Subject: Re: lousy disk perf. under cpu load (was IDE vs SCSI) In-Reply-To: <199709091834.LAA28493@usr04.primenet.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@freebsd.org X-Loop: FreeBSD.org Precedence: bulk On Tue, 9 Sep 1997, 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. The NCR driver has supported tags for a LONG time, probably since before 2.1 The ahc driver has supported tages for a LONG time, since about 2.1.5 ... > > PS How do I find out if tagged queueing is supported? Maybe time > > to try -current? > > Look in the archives or look in the archives to get Stefan's address, > and ask him. Or if you CVSup/CTM code, look at the CVS logs. "ncrcontrol" for the NCR driver. Also, see ncrcontrol man page. The ahc driver lists tag support during boot. Also see ahc man page. > Terry Lambert > terry@lambert.org > --- > Any opinions in this posting are my own and not those of my present > or previous employers. > Tom