From owner-freebsd-isp Tue Nov 5 15:21:18 1996 Return-Path: owner-isp Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id PAA02354 for isp-outgoing; Tue, 5 Nov 1996 15:21:18 -0800 (PST) Received: from brasil.moneng.mei.com (brasil.moneng.mei.com [151.186.109.160]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id PAA02346 for ; Tue, 5 Nov 1996 15:21:13 -0800 (PST) Received: (from jgreco@localhost) by brasil.moneng.mei.com (8.7.Beta.1/8.7.Beta.1) id RAA07444; Tue, 5 Nov 1996 17:18:40 -0600 From: Joe Greco Message-Id: <199611052318.RAA07444@brasil.moneng.mei.com> Subject: Re: /usr/obj size To: richardc@CSUA.Berkeley.EDU (Veggy Vinny) Date: Tue, 5 Nov 1996 17:18:39 -0600 (CST) Cc: jgreco@brasil.moneng.mei.com, michaelv@MindBender.serv.net, isp@FreeBSD.org, chad@gaianet.net, johnnyu@accessus.net, mario1@PrimeNet.Com In-Reply-To: from "Veggy Vinny" at Nov 5, 96 01:27:07 pm X-Mailer: ELM [version 2.4 PL24] Content-Type: text Sender: owner-isp@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk > On Tue, 5 Nov 1996, Joe Greco wrote: > > > > The reason I keep saying 2GB is because that seems to be the current > > > "sweet spot" where the price per gigabyte is lowest, and the > > > performanc is at least "good". > > > > For price, 2GB is your ticket. For performance, 1GB is (I have recently > > paid the "premium" to get a dozen and a half ST-31055N's... ouch... it > > hurts, but you get almost double the throughput for having spent about > > 30% more than the 2GB drives would have cost). > > Hmmm, speaking about 2 GIG drives, the new Barracuda's are cheaper > than the ST32550N, I wonder if any performance is sacraficed since it has > half the cache but come in both UltraSCSI and UltraSCSI Wide versions. > Never thought about it but 5 2 GIG drives are cheaper than a single 9 gig > drive, I always thought the bigger the drive, the less the cost per > megabyte. Think about this: Two drives each with half the cache of a larger drive have the same amount of cache, total, as the larger drive. Two drives have twice the heads of a larger drive. Two drives do not cost too much more than the larger drive. Let us say it costs 30% more. If you buy the larger drive and find it is too slow, you buy the two smaller drives and then you have spent 130% more. (But you have an additional drive.) > > > Of course 7200RPM drives are faster. But, if you can buy an extra > > > drive or two, and put that in the stripe set, with the money you save > > > by going 5400RPM, that extra drive might just make up the difference > > > in speed. So, to say it the other way around: no, you don't need > > > 7200RPM drives. > > > > Yes. I will put a two-disk stripe of a pair of ST-31055N Hawk-2 drives > > (9ms, 5400RPM, etc) up against a single ST-32550N Barracuda (8ms, 7200RPM) > > any day and beat it by a fair margin. And relatively speaking, with the > > 32550N's hovering around $650 and 31055N's around $320, tell me what > > makes more sense to do :-) > > > > But I will grant that the 32155N's, in the low 5's are attractive too. > > Hmmm, I know I just asked this. but how does striping work and is > it only for SCSI drives? Striping ("CCD") works on general disk devices. I have never tried it on non-SCSI drives or with non-PCI controllers. ... JG