From owner-freebsd-current@FreeBSD.ORG Fri Jan 26 19:48:16 2007 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id E1C1216A4C7 for ; Fri, 26 Jan 2007 19:48:16 +0000 (UTC) (envelope-from anderson@freebsd.org) Received: from mh1.centtech.com (moat3.centtech.com [64.129.166.50]) by mx1.freebsd.org (Postfix) with ESMTP id A068E13C458 for ; Fri, 26 Jan 2007 19:48:16 +0000 (UTC) (envelope-from anderson@freebsd.org) Received: from [192.168.42.21] (andersonbox1.centtech.com [192.168.42.21]) by mh1.centtech.com (8.13.8/8.13.8) with ESMTP id l0QJ9T15056585; Fri, 26 Jan 2007 13:09:29 -0600 (CST) (envelope-from anderson@freebsd.org) Message-ID: <45BA51EA.3070901@freebsd.org> Date: Fri, 26 Jan 2007 13:09:30 -0600 From: Eric Anderson User-Agent: Thunderbird 1.5.0.9 (X11/20070121) MIME-Version: 1.0 To: Warner Losh References: <20070125.192448.-432840241.imp@bsdimp.com> <200701261052.12435.shoesoft@gmx.net> <20070126.114944.104080809.imp@bsdimp.com> In-Reply-To: <20070126.114944.104080809.imp@bsdimp.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV 0.88.4/2493/Fri Jan 26 06:00:46 2007 on mh1.centtech.com X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=8.0 tests=BAYES_00 autolearn=ham version=3.1.6 X-Spam-Checker-Version: SpamAssassin 3.1.6 (2006-10-03) on mh1.centtech.com Cc: freebsd-current@freebsd.org, shoesoft@gmx.net Subject: Re: Interesting speed benchmarks X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Jan 2007 19:48:17 -0000 On 01/26/07 12:49, Warner Losh wrote: > From: Stefan Ehmann > Subject: Re: Interesting speed benchmarks > Date: Fri, 26 Jan 2007 10:52:11 +0100 > >> On Friday 26 January 2007 03:24, M. Warner Losh wrote: >>> On a lark, I just got a combo USB/Firewire external disk drive. I ran >>> some crude benchmarks, and I was surprised by what I found. This is >>> on a fairly stock -current kernel. >>> >>> Firewire does around 40MB/s, while USB 2.0 maxes out at about 12MB/s. >>> This is with a simple dd command: >> On my i386 notebook with USB 2.0 enclosure. >> Linux: 31.5MB/s >> FreeBSD: 27.5MB/s >> >> There's still room for improvement but numbers don't seem that bad. >> >> Maybe you should try knoppix or so to verify it's not the drive's fault. Other >> than that I'd also guess it's an amd64 problem. > > It is not an AMD64 problem. I get the same numbers on my i386 latpop > as I get on my amd64 laptop. Actually, I get WORSE numbers on the > i386 laptop by about 20%. > > It isn't the drive's fault. Otherwise, firewire wouldn't get 40MB/s. > The same drive, the same enclusure are used for both the USB and > firewire tests. It is about as apples to apples as you can get. > > There's some serious performance issues in the usb stack. > > Warner A few tidbits of information (may be useful, maybe not): - I've seen the firewire part of the enclosure be faster than the USB part. The chips that run it are possibly different, so that shouldn't be forgotten. I've had a few USB->flash adapters that got lousy performance, but when I switched to a USB->SATA flash card reader, the performance doubled. - For those testing using a file system - STOP! It's not a good test of the throughput of the device, and depends on a lot of variables. dd or diskinfo are decent generic tools, but in Windows you just can't use a file system benchmark to compare. - If you read/write less than the drive cache, it should remove the latency of the drive from the equation, right? Eric