From owner-freebsd-hackers Wed Sep 11 21:46:32 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id VAA04853 for hackers-outgoing; Wed, 11 Sep 1996 21:46:32 -0700 (PDT) Received: from ottawa.net (ppp-91.ottawa.net [205.211.4.91]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id VAA04847 for ; Wed, 11 Sep 1996 21:46:28 -0700 (PDT) Received: (from brianc@localhost) by ottawa.net (8.7.5/8.7.3) id AAA08120 for freebsd-hackers@FreeBSD.org; Thu, 12 Sep 1996 00:45:26 -0400 (EDT) From: Brian Campbell Message-Id: <199609120445.AAA08120@ottawa.net> Subject: Re: IDE and ASUS P/I-P6NP5 To: freebsd-hackers@FreeBSD.org (FreeBSD Hackers) Date: Thu, 12 Sep 1996 00:45:26 -0400 (EDT) In-Reply-To: <199609120411.VAA24398@MindBender.serv.net> from "Michael L. VanLoon -- HeadCandy.com" at "Sep 11, 96 09:11:43 pm" Reply-to: brianc@pobox.com X-Mailer: ELM [version 2.4ME+ PL22 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk > >Nonetheless I'd really love to have a bus-mastering IDE driver > >available. I could care less if it automatically detects older > >hardware, although other operating systems manage to do this. > > Yes, I agree this would be great. We should make the most of all our > hardware... > > >I'd be happy to manually specify that my IDE chipset and drive were > >"DMA capable" for the dual benefit of freeing up the CPU for more > >useful tasks and increased throughput. > > But you still shouldn't kid yourself that it would be "as good as" > SCSI. All the design deficiencies of IDE aside, the single most > important benefit to asynchronous high speed drive through-put that I > have found in my testing, is tagged-command-queuing. Even over the > same high end SCSI board (AHC-2940UW or BT956c) on the same drives, > with tagged-command-queuing simply disabled. Unless things have changed since I last bought a machine, it's cheaper to buy a machine with an IDE drive than SCSI drive. Perhaps because the IDE (dual) controller is built into the motherboard chipset, or perhaps because IDE drives are often cheaper (regardless of whether this is changing). Mine came with both an IDE hard drive and an IDE cdrom. I don't imagine this changes much, given the builtin IDE support, even if you're building your own system. Which isn't to say I don't agree SCSI is a better all-round solution. I also have a 2940U, a SCSI drive and two SCSI cdroms. But having SCSI doesn't mean I don't want to take the best advantage I can of the cheap, common IDE controller/drive I've got as well.