From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 2 May 2002 18:28:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 2 May 2002 18:28:49 -0400 Received: from adsl-67-113-154-34.dsl.sntc01.pacbell.net ([67.113.154.34]:2553 "EHLO postbox.aslab.com") by vger.kernel.org with ESMTP id ; Thu, 2 May 2002 18:28:48 -0400 Message-ID: <09fa01c1f227$c8357f00$6502a8c0@jeff> From: "Jeff Nguyen" To: =?iso-8859-1?Q?Jakob_=D8stergaard?= , "Alan Cox" Cc: "Martin Dalecki" , "Pavel Machek" , "Roy Sigurd Karlsbakk" , In-Reply-To: <20020502215833.V31556@unthought.net> <20020502231359.W31556@unthought.net> Subject: Re: IDE hotplug support? Date: Thu, 2 May 2002 15:22:00 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org You can get a sustained read speed of 80MB/s on the Adaptec 2000S Zero Channel RAID with 7 drives (RAID-5). But the sustained write speed is only around 32MB/s. On the other hand, the 3Ware Escalade 7850 can sustain a read speed of 130MB/s with 8 drives (RAID-5). The write speed is 30MB/s. Jeff ----- Original Message ----- From: "Jakob Østergaard" To: "Alan Cox" Cc: "Martin Dalecki" ; "Pavel Machek" ; "Roy Sigurd Karlsbakk" ; Sent: Thursday, May 02, 2002 2:13 PM Subject: Re: IDE hotplug support? > On Thu, May 02, 2002 at 09:26:38PM +0100, Alan Cox wrote: > > > >=20 > > > > 8 x 130MBy/s >>>> PCI bus throughput... I would rather recommend > > > > a classical RAID controller card for this kind of > > > > setup. > > > > > > Because RAID controllers do not use the PCI bus ??? ;) > > > > The raid card transfers the data once, software raid once per device for > > Raid 1/5 - thats a killer. > > For RAID-1 it's a killer (for writes), I agree. > > But I really doubt it would be so horrible for RAID-5 - after all, it's only > one extra block (the parity block) for each N-1 blocks written (for an N disk > RAID-5). The penalty should be less, the more disks you have in the array. > > But seriously, has anyone out there ever seen a hardware RAID controller with > a *sustained* RAID-5 thoughput of more than 60 MB/sec ? Not that I think it > is impossible, but I've never heard about it. Enlighten me, please, and not > with marketing numbers... > > > > > > By the way, has anyone tried such larger multi-controller setups, and t= > > > ested > > > the bandwidth in configurations with multiple PCI busses on the board, = > > > versus a > > > single PCI bus ? > > > > With 2.4 yes. With all the 2.5 changes no. > > Did you get any speedup ? Were you close to PCI bus saturation in the one-bus > scenario ? > > -- > ................................................................ > : jakob@unthought.net : And I see the elder races, : > :.........................: putrid forms of man : > : Jakob Østergaard : See him rise and claim the earth, : > : OZ9ABN : his downfall is at hand. : > :.........................:............{Konkhra}...............: > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >