From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicola Fankhauser Subject: Re: dd version I used is 5.2.1, but... Date: Wed, 02 Mar 2005 10:43:05 +0100 Message-ID: <42258AA9.9090000@variant.ch> References: <4224C871.2000802@variant.ch> <20050302074533.GA5347@middle.of.nowhere> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit In-Reply-To: <20050302074533.GA5347@middle.of.nowhere> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids hi Jurriaan wrote: > - please group messages in the same thread, thank you. sorry for that. > - if there is no answer within a day, wait some more - not everybody is > constantly reading this list, you know. thanks for the tip. > - wrt your question: how are those raid-controllers on your motherboard? actually, I could not find very much info about this. all I know is: 1. the SiI 3114 chip is (by specification of the chip, found at SiI's site) connected by a PCI bus, 32bit wide, at 66mhz. however, I don't know whether Asus chose to connect it at 33mhz. lspci says it's 66mhz, but is this information trustworthy? nvidia tech specs of nforce4 sli (the chipset I have) says its PCI bridges are 33mhz only [1]. 2. the nforce4 sata ports are (to my knowledge) directly connected to the nforce4 chipset. > If they are all connected through a single pci-bus, the speed is > reasonable. The best way to test if it's your motherboard or your > raid, is to start multiple dd processes on different disks, or > multiple bonnie++ processes on different disks, all concurrently, of > course. good idea (thought about it too). results of concurrent reads on all eight drives show that the nforce4 sata ports perform quite well at 211MiB/s (52MiB/s per drive), however the SiI 3114 seemed to saturate at 129MiB/s (32MiB/s per drive). added, this gives at total throughput of 340MB/s. non-concurrent dd gives for both controllers values seemingly bound by drive performance of 60MiB/s. thanks & regards nicola [1]: http://nvidia.com/page/pg_20041015917263.html