From owner-freebsd-questions@FreeBSD.ORG Sat Aug 30 15:08:25 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 45B1616A4BF for ; Sat, 30 Aug 2003 15:08:25 -0700 (PDT) Received: from agora.rdrop.com (agora.rdrop.com [199.26.172.34]) by mx1.FreeBSD.org (Postfix) with ESMTP id 625AA43F75 for ; Sat, 30 Aug 2003 15:08:22 -0700 (PDT) (envelope-from alan@agora.rdrop.com) Received: from agora.rdrop.com (202@localhost [127.0.0.1]) by agora.rdrop.com (8.12.7/8.12.7) with ESMTP id h7UM8FmV083994 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Sat, 30 Aug 2003 15:08:15 -0700 (PDT) (envelope-from alan@agora.rdrop.com) Received: (from alan@localhost) by agora.rdrop.com (8.12.7/8.12.9/Submit) id h7UM8E51083993; Sat, 30 Aug 2003 15:08:14 -0700 (PDT) Date: Sat, 30 Aug 2003 15:08:14 -0700 From: Alan Batie To: freebsd-questions@freebsd.org Message-ID: <20030830220814.GA80664@agora.rdrop.com> Mail-Followup-To: freebsd-questions@freebsd.org References: <20030828212015.GC32069@agora.rdrop.com> <20030830213526.GA76426@agora.rdrop.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-md5; protocol="application/pgp-signature"; boundary="WIyZ46R2i8wDzkSu" Content-Disposition: inline In-Reply-To: <20030830213526.GA76426@agora.rdrop.com> User-Agent: Mutt/1.5.4i Subject: USB 2 & umass X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 30 Aug 2003 22:08:25 -0000 --WIyZ46R2i8wDzkSu Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable OK, the point of this whole exercise was to find out if what I'd heard about USB 2 being half duplex and thus a bad idea for RW mass storage was true. It looks like it, but on the other hand, it looks like I'm only running at USB 1 speeds too: /mnt is the USB drive, which has a fresh FreeBSD installation on it for something else, so I'm playing in /mnt/tmp for the USB side, and /tmp for the native IDE side: [72] $ cat ../kernel ../kernel > k [73] $ time cat k k > k2 real 0m15.408s [77] $ time cat k2 k2 > k4 real 0m32.561s [78] $ lf -l k4 -rw-r--r-- 1 alan wheel 32978776 Aug 30 14:42 k4 =2E..so, about 1MB/s [81] $ time cat k4 > /tmp/k4 real 0m2.946s =2E..on the other hand, unidirectional USB->IDE gets 10MB/s (an old 6G Quantum Fireball, not a fast drive, but this does imply that it's running faster than USB 1's 12Mb/s, which would be 1.5MB/s absolute best case) [82] $ cd /tmp [83] $ time cat k4 k4 > k8 real 0m5.917s =2E..a little over 10MB/s [85] $ time cat k8 > /mnt/tmp/k8 real 1m5.876s =2E..and back to 1MB/s IDE->USB (r/w'ing directory/inode info?) [87] $ lf -l k8 -rw-r--r-- 1 alan wheel 65957552 Aug 30 14:43 k8 I also just noticed this tidbit in the boot messages, FWIW: (da0:umass-sim0:0:0:0): READ(6)/WRITE(6) not supported, increasing minimum_= cmd_size to 10. On the other hand, this: [95] $ time cat k8 > /dev/null real 0m51.805s =2E..which, at about 1+MB/s implies the 10MB/s above was a cache effect, and thus the question: why is this thing running at USB 1 speeds? --=20 Alan Batie ______ alan.batie.org Me alan at batie.org \ / www.qrd.org The Triangle PGPFP DE 3C 29 17 C0 49 7A \ / www.pgpi.com The Weird Numbers 27 40 A5 3C 37 4A DA 52 B9 \/ spamassassin.taint.org NO SPAM! To announce that there must be no criticism of the President, or that we are to stand by the President, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public. -Theodore Roosevelt, 26th US President (1858-1919) --WIyZ46R2i8wDzkSu Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.2 (FreeBSD) iQCVAwUBP1EgTov4wNua7QglAQHBvQQA0nYeUQJyKhwCCKkzicjN5SrEvyBIE8FS su6A/0xi9BSHrQD9U388F2DXxzGXlnHeiZdEIDjxo1T6vdY4FQVvoMS8VUM4Eskh 3h/uCR/QnfYPv/GJE1M6o3brNcuhOGS1eh4LswoxrJe4yjsCO1ZMTFJSzzf3+CJP IL3/oofLbvY= =yWc+ -----END PGP SIGNATURE----- --WIyZ46R2i8wDzkSu--