From owner-freebsd-questions@FreeBSD.ORG Mon Jan 15 20:15:10 2007 Return-Path: X-Original-To: questions@freebsd.org Delivered-To: freebsd-questions@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id B1CBC16A40F for ; Mon, 15 Jan 2007 20:15:10 +0000 (UTC) (envelope-from roberthuff@rcn.com) Received: from smtp02.lnh.mail.rcn.net (smtp02.lnh.mail.rcn.net [207.172.157.102]) by mx1.freebsd.org (Postfix) with ESMTP id 54C1E13C44B for ; Mon, 15 Jan 2007 20:15:09 +0000 (UTC) (envelope-from roberthuff@rcn.com) Received: from mr02.lnh.mail.rcn.net ([207.172.157.22]) by smtp02.lnh.mail.rcn.net with ESMTP; 15 Jan 2007 15:15:09 -0500 Received: from smtp01.lnh.mail.rcn.net (smtp01.lnh.mail.rcn.net [207.172.4.11]) by mr02.lnh.mail.rcn.net (MOS 3.7.5a-GA) with ESMTP id MTY70149; Mon, 15 Jan 2007 15:15:08 -0500 (EST) Received: from 209-6-203-219.c3-0.smr-ubr1.sbo-smr.ma.cable.rcn.com (HELO jerusalem.litteratus.org.litteratus.org) ([209.6.203.219]) by smtp01.lnh.mail.rcn.net with ESMTP; 15 Jan 2007 15:15:07 -0500 From: Robert Huff MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17835.57498.217769.264779@jerusalem.litteratus.org> Date: Mon, 15 Jan 2007 15:14:18 -0500 To: questions@freebsd.org In-Reply-To: <200701141603.l0EG3Zk8001981@jerusalem.litteratus.org> References: <200701141603.l0EG3Zk8001981@jerusalem.litteratus.org> X-Mailer: VM 7.17 under 21.5 (beta27) "fiddleheads" XEmacs Lucid X-Junkmail-Status: score=10/50, host=mr02.lnh.mail.rcn.net X-Junkmail-SD-Raw: score=unknown, refid=str=0001.0A090208.45ABDEE2.001B,ss=1,fgs=0, ip=207.172.4.11, so=2006-05-09 23:27:51, dmn=5.2.125/2006-10-10 Cc: Subject: USB 2.0: realistic transfer speeds? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 Jan 2007 20:15:10 -0000 I'm testing a possible new backup arrangement, involving an external hard disk connected by USB 2.0. Now the quoted 60 mbyte/sec is obviously the "maximum theoretical rate"; however, it seemed reasonable to get 30, 20 or even 15. Instead it's having trouble breaking the 10 barrier, and some operations are never make it past 6. (Which is better than the ~1 from a USB 1.1 connection, but still ....) So - for those who have experience with bulk transfers across USB or good theoretical knowledge: what's a reasonable number? (Background information: this is driven by the stock dump that comes with: FreeBSD 7.0-CURRENT #0: Tue Nov 14 17:38:15 EST 2006 and my hardware list is appended. (I'm curious more than concerned about the [GIANT-LOCK] and "Uninitialized Transport 5:0?".)) Robert Huff Jan 14 10:07:55 kernel: ehci0: mem 0xf0000000-0xf00000ff irq 15 at device 10.3 on pci0 Jan 14 10:07:55 kernel: ehci0: [GIANT-LOCKED] Jan 14 10:07:55 kernel: usb3: on ehci0 Jan 14 10:07:55 kernel: umass0: on uhub3 Jan 14 10:07:55 kernel: (probe15:umass-sim0:0:0:0): Uninitialized Transport 5:0? Jan 14 10:07:55 kernel: da2 at umass-sim0 bus 0 target 0 lun 0 Jan 14 10:07:55 kernel: da2 at umass-sim0 bus 0 target 0 lun 0 Jan 14 10:07:55 kernel: da2: Fixed Direct Access SCSI-0 device Jan 14 10:07:55 kernel: da2: 40.000MB/s transfers Jan 14 10:07:55 kernel: da2: 95611MB (195813072 512 byte sectors: 255H 63S/T 12188C)