From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1RIS8s-0002e1-8o for garchives@archives.gentoo.org; Mon, 24 Oct 2011 21:33:10 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 4774E21C0EE; Mon, 24 Oct 2011 21:32:56 +0000 (UTC) Received: from smtp.gentoo.org (smtp.gentoo.org [140.211.166.183]) by pigeon.gentoo.org (Postfix) with ESMTP id D67E621C021 for ; Mon, 24 Oct 2011 21:32:00 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp.gentoo.org (Postfix) with ESMTP id 55B811B400E for ; Mon, 24 Oct 2011 21:32:00 +0000 (UTC) X-Virus-Scanned: by amavisd-new using ClamAV at gentoo.org X-Spam-Score: -4.011 X-Spam-Level: X-Spam-Status: No, score=-4.011 required=5.5 tests=[AWL=-0.219, BAYES_00=-1.9, DKIM_ADSP_CUSTOM_MED=0.001, FREEMAIL_FROM=0.001, NML_ADSP_CUSTOM_MED=0.9, RCVD_IN_DNSWL_MED=-2.3, RP_MATCHES_RCVD=-0.504, T_TO_NO_BRKTS_FREEMAIL=0.01] Received: from smtp.gentoo.org ([127.0.0.1]) by localhost (smtp.gentoo.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id l2C1wqnuFeZs for ; Mon, 24 Oct 2011 21:31:54 +0000 (UTC) Received: from lo.gmane.org (lo.gmane.org [80.91.229.12]) by smtp.gentoo.org (Postfix) with ESMTP id CEFBB1B4016 for ; Mon, 24 Oct 2011 21:31:51 +0000 (UTC) Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1RIS7Z-0006qf-CU for gentoo-user@gentoo.org; Mon, 24 Oct 2011 23:31:49 +0200 Received: from dsl.comtrol.com ([64.122.56.22]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 24 Oct 2011 23:31:49 +0200 Received: from grant.b.edwards by dsl.comtrol.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 24 Oct 2011 23:31:49 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: gentoo-user@lists.gentoo.org From: Grant Edwards Subject: [gentoo-user] Re: [OT] Disappointing USB3 performance Date: Mon, 24 Oct 2011 21:31:37 +0000 (UTC) Message-ID: References: <4EA5D5D7.20205@binarywings.net> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: dsl.comtrol.com User-Agent: slrn/pre0.9.9-102 (Linux) X-Archives-Salt: X-Archives-Hash: db4e6098fae14e54ffff2c5d90714aea On 2011-10-24, Florian Philipp wrote: > Am 24.10.2011 22:02, schrieb Grant Edwards: >> On 2011-10-24, walt wrote: >> >>> I just bought an add-on USB3 adapter and outboard USB3/sata docking >>> station, and I've been comparing the performance with my old e-sata >>> outboard docking station. Not so good :( >>> >>> After getting some unreliable results with hdparm, I settled on >>> copying one 3GB file from one partition of the outboard drive to >>> another partition of the same drive. These results are highly >>> reproducible, and favor e-sata over USB3 by a large margin. >>> >>> Over at least six trials on each docking station I consistently get >>> 105 seconds for USB and 84 seconds for e-sata, a 5:4 ratio in favor >>> of e-sata. >> >> Not surprising. Did you expect that adding a gateway device to the >> communication path and another protocol layer on top of SATA would >> make things faster? >> >>> I used the same hard disk and the same pci-e slot in the same >>> minimally-loaded machine for all the runs, and got very consistent >>> results every time. >>> >>> Basically, the USB3/sata docking station gets the same throughput as >>> the older sata 1 drives connected to the onboard pci sata controller, >>> which is still pretty respectable for an outboard drive, I think. >> >> Yep, SATA performs the same as SATA. AFAIK, eSATA and SATA are >> identical apart from the physical specs for the connector, a few minor >> voltage level differences (to imporove noise tolerance), and hot-plug >> support. > > Normal SATA also offers hotplug. Usually works, too. I read somewhere that not all controllers support hotplug on "internal" connectors, but I can't personally attest to having found one that didn't. >>> So, has anyone out there done similar tests on USB3 drives yet? >> >> There are disk drives that talk USB3 natively and aren't just using >> USB<->SATA gateways? > > Well, there is USB Attached SCSI (CONFIG_USB_UAS in the kernel). It > supports command queuing and works for USB-2.0 and 3.0 (but has > additional software overhead for USB-2.0). I've not yet seen a > compatible device, though. Interesting. Is USB3 peer to peer like SCSI and Firewire, or is it the same master/slave poll/response scheme that has always crippled USB? Doing SCSI via a poll/response transport protocol seems like it would lose most of the advantages of SCSI. -- Grant Edwards grant.b.edwards Yow! He is the MELBA-BEING at ... the ANGEL CAKE gmail.com ... XEROX him ... XEROX him --