From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Mudama Subject: Re: sata_promise performance observations Date: Mon, 25 Oct 2004 11:55:28 -0600 Sender: linux-ide-owner@vger.kernel.org Message-ID: <311601c904102510555d7c0810@mail.gmail.com> References: <417A1826.5010502@wasp.net.au> Reply-To: Eric Mudama Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from rproxy.gmail.com ([64.233.170.192]:61124 "EHLO rproxy.gmail.com") by vger.kernel.org with ESMTP id S261233AbUJYRzc (ORCPT ); Mon, 25 Oct 2004 13:55:32 -0400 Received: by rproxy.gmail.com with SMTP id 77so457460rnk for ; Mon, 25 Oct 2004 10:55:28 -0700 (PDT) In-Reply-To: <417A1826.5010502@wasp.net.au> List-Id: linux-ide@vger.kernel.org To: Brad Campbell Cc: linux-ide@vger.kernel.org arbitration between the multiple PCI cards? A single card that doesn't have to compete for PCI resources would, in theory, be faster... (Don't know much about this chunk of hardware, 'tis only a guess) On Sat, 23 Oct 2004 12:36:54 +0400, Brad Campbell wrote: > G'day all, > > Interesting observation with 3 SATA150TX4 cards and 10 Maxtor Maxline-II 250GB SATA drives. > > If I run a concurrent dd if=/dev/sda > /dev/null and dd if=/dev/sdb > /dev/null I get the expected > 115MB/s transfer rates in vmstat. > > If I do a dd if=/dev/sda > /dev/null and dd if=/dev/sde > /dev/null I get about 80MB/s > > sda, sde & sdi I get > procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu---- > > 3 0 22540 2560 463908 5320 0 0 85294 16 1102 761 11 88 0 1 > 3 1 22540 1480 464852 5320 0 0 86493 25 987 512 13 86 0 0 > 2 2 22540 2176 464304 5268 0 0 86774 18 1091 721 12 87 0 1 > 2 2 22540 1488 464860 5368 0 0 85562 18 921 416 13 87 0 0 > > When streaming from drives not on the same controller, I lose about 30mb/s transfer rate. In fact, > it seems to max out at about 86MB/s no matter what combination of drives I use if I stream from more > than one controller. > > However, if I use sda, sbb & sdc I get > > procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu---- > > 0 3 22512 1768 464448 5304 0 0 121661 18 1257 566 9 59 0 32 > 0 3 22512 1536 464696 5316 0 0 122903 14 1262 578 10 59 0 31 > 0 3 22512 2112 464228 5268 0 0 121655 14 1255 578 9 60 0 32 > > How bizzare. I have latency set to 32 on all controllers, but I have tried as low as 8 and as high > as 128 to no avail. > > I have readahead set to 4096 on all devices. > > Anyone have any ideas? > > Not that this is an issue for me (I'm only using it as a fileserver over GB eth so its not like > 100MB/s is actually required, just an interesting observation) > > Regards, > Brad > - > To unsubscribe from this list: send the line "unsubscribe linux-ide" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >