From owner-freebsd-stable@FreeBSD.ORG Thu Jul 26 01:14:42 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1E42516A41B for ; Thu, 26 Jul 2007 01:14:42 +0000 (UTC) (envelope-from hg@queue.to) Received: from pickle.queue.to (pickle.queue.to [71.180.69.18]) by mx1.freebsd.org (Postfix) with ESMTP id 99F2213C457 for ; Thu, 26 Jul 2007 01:14:41 +0000 (UTC) (envelope-from hg@queue.to) Received: (qmail 62344 invoked from network); 25 Jul 2007 21:14:40 -0400 Received: from cally.queue.to (172.16.0.6) by pickle.queue.to with ESMTP; 25 Jul 2007 21:14:40 -0400 Message-ID: <46A7F580.6000005@queue.to> Date: Wed, 25 Jul 2007 21:14:40 -0400 From: Howard Goldstein User-Agent: Thunderbird 2.0.0.5 (X11/20070720) MIME-Version: 1.0 To: Scott Long References: <46A4E8FA.6010403@queue.to> <46A7B3FB.7010504@queue.to> <46A7B7AF.6080308@samsco.org> <46A7BF8C.5020909@queue.to> <46A7F2C2.2090009@samsco.org> In-Reply-To: <46A7F2C2.2090009@samsco.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org Subject: Re: [resolved, naively] Re: geom vs ich through ar device - benchmarks? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Jul 2007 01:14:42 -0000 Scott Long wrote: > Howard Goldstein wrote: > >> Scott Long wrote: >> >>> Howard Goldstein wrote: >>> >>>> Testbed: Pair of WDC3200AAKS 320gb SATA, freshly newfsd 10gb filesystem >>>> mounted with softupdates, remounted after each test >>>> P4 @ 3ghz on a P4P800 in 6.2-STABLE, single user mode, ICH5R controller >>>> detects these SATA-II drives inexplicably as SATA-I >>>> >>>> >>> ICH5 only support SATA-1. >>> >> Dang. Does anyone yield SATA-II speeds with the a PCI controller? I'm >> not sure if 25-30MB/s is even possible with regular PCI >> >> > > Even PCI-33 should be able to sustain about 100MB/s, enough to handle a > single disk drive. Many controller are PCI-X or PCIe now, which has > plenty of bandwidth for 4-8 drives. > > Sorry I dropped a zero as my stupid test showed 76-77MB/s. I think I should perhaps throw in the towel as the manual for this old P4P800 claims its "32 bit PCI 2.2 support ... 133MB/s maximum" >>>> Of course after this I used gmirror... >>>> >>> Just so we're clear, the ICH5 doesn't have any firmware and doesn't >>> >>> actually do any RAID operations. What is has is hook into the system >>> BIOS during boot. That hook allows the BIOS to do RAID-like operations >>> during boot, until the OS takes over control of the devices. After >>> that, it's up to the OS to do all the RAID work. The 'ar' driver is >>> still software RAID, just like gmirror. What you've effectively done >>> merely compare the performance of one software RAID stack to another. >>> That's certainly an interesting comparison, but maybe not exactly what >>> you had in mind. >>> >>> >> It's helpful - thank you. Do you think I'm correct in assuming the >> interface is pretty much saturated at this point and if I wanted >> additional speed I'd need to start thinking bringing in additional or >> faster interfaces? >> > > You should be able to sustain at least 70MB/s on a single modern drive > with SATA-1 or SATA-2. If you're not getting that then something in the > driver or the application is getting in the way. Even with the, um, > "problems" that SiI controllers are famous for, you should be able to > sustain a decent data rate on a single drive. > Thank you, Scott