From owner-freebsd-current@FreeBSD.ORG Fri Jan 26 21:09:49 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 B4CD016A401; Fri, 26 Jan 2007 21:09:49 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (vc4-2-0-87.dsl.netrack.net [199.45.160.85]) by mx1.freebsd.org (Postfix) with ESMTP id 5531713C49D; Fri, 26 Jan 2007 21:09:49 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.13.4/8.13.4) with ESMTP id l0QL7U5C049201; Fri, 26 Jan 2007 14:07:30 -0700 (MST) (envelope-from imp@bsdimp.com) Date: Fri, 26 Jan 2007 14:07:56 -0700 (MST) Message-Id: <20070126.140756.-311940260.imp@bsdimp.com> To: anderson@freebsd.org From: "M. Warner Losh" In-Reply-To: <45BA51EA.3070901@freebsd.org> References: <200701261052.12435.shoesoft@gmx.net> <20070126.114944.104080809.imp@bsdimp.com> <45BA51EA.3070901@freebsd.org> X-Mailer: Mew version 4.2 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.0 (harmony.bsdimp.com [127.0.0.1]); Fri, 26 Jan 2007 14:07:31 -0700 (MST) 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 21:09:49 -0000 In message: <45BA51EA.3070901@freebsd.org> Eric Anderson writes: : 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. I'm now seeing on my FreeBSD desktop at work numbers that are in the 28MB/s range. I'll have to investigate things more closely... I can't imagine why FreeBSD/amd64 would be so much slower. : - 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. yes. : - If you read/write less than the drive cache, it should remove the : latency of the drive from the equation, right? True, but not relevant, I don't think. the speed of the disk is in excess of what either firewire or usb can do. Warner