From owner-freebsd-hardware@FreeBSD.ORG Wed Jun 25 15:24:08 2008 Return-Path: Delivered-To: freebsd-hardware@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 34EE61065679 for ; Wed, 25 Jun 2008 15:24:08 +0000 (UTC) (envelope-from soralx@cydem.org) Received: from pd2mo2so.prod.shaw.ca (idcmail-mo1so.shaw.ca [24.71.223.10]) by mx1.freebsd.org (Postfix) with ESMTP id 14F9B8FC20 for ; Wed, 25 Jun 2008 15:24:07 +0000 (UTC) (envelope-from soralx@cydem.org) Received: from pd3mr1so.prod.shaw.ca (pd3mr1so-qfe3.prod.shaw.ca [10.0.141.177]) by l-daemon (Sun ONE Messaging Server 6.0 HotFix 1.01 (built Mar 15 2004)) with ESMTP id <0K3000AB6YQE4J20@l-daemon> for freebsd-hardware@freebsd.org; Wed, 25 Jun 2008 09:23:02 -0600 (MDT) Received: from pn2ml4so.prod.shaw.ca ([10.0.121.148]) by pd3mr1so.prod.shaw.ca (Sun Java System Messaging Server 6.2-7.05 (built Sep 5 2006)) with ESMTP id <0K300062UYQDX530@pd3mr1so.prod.shaw.ca> for freebsd-hardware@freebsd.org; Wed, 25 Jun 2008 09:23:02 -0600 (MDT) Received: from soralx ([24.87.3.133]) by l-daemon (Sun ONE Messaging Server 6.0 HotFix 1.01 (built Mar 15 2004)) with ESMTP id <0K3000CZHYQCLI30@l-daemon> for freebsd-hardware@freebsd.org; Wed, 25 Jun 2008 09:23:00 -0600 (MDT) Date: Wed, 25 Jun 2008 08:23:01 -0700 From: soralx@cydem.org In-reply-to: <50A3BEAB67F03F44A2A063D55FC14D37119163@sbs2003.Webline.local> To: freebsd-hardware@freebsd.org Message-id: <20080625082301.36dcc2d0@soralx> MIME-version: 1.0 X-Mailer: Claws Mail 3.3.1 (GTK+ 2.12.9; i386-portbld-freebsd7.0) Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit References: <50A3BEAB67F03F44A2A063D55FC14D37119163@sbs2003.Webline.local> Cc: alwin.roosen@webline.be Subject: Re: Would a Transcend USB Flash Module of 2GB work? X-BeenThere: freebsd-hardware@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: General discussion of FreeBSD hardware List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 Jun 2008 15:24:08 -0000 > [...] > I am also wondering if it is a good approach to use USB dongles, > instead of real Solid State devices on ATA. I see a lot of USB problems > in the Mailing list Archives (see link below as example). I don't > understand all of that, and I know there are many USB devices which can > cause these issues. My hardware supplier recommends the USB dongles, > because they are cheaper and easier to install (just plug it in an 10-pin > USB port on the motherboard). > [...] I'm a bit short on time at the moment, I shall be brief. I could expand on this later, be sure to remind me. USB flash drives don't work for anything other that temporary portable storage. They are _completely_ useless for keeping base system on, even if you have lots of RAM and don't need speed. I tried 4 USB drives (30MB/s read, 20MB/s writes datasheet) connected to two EHCI mainboard headers, striped in ZFS. Totally useless. The avg real life write speeds are ~5MB/s, reads ~12-20 MB/s, (four 'dd' reads give total 80MB/s), and the whole array is only good for about one(!) IOPS. The whole system freezes for seconds or tens of seconds at times. I'm not sure if it's hadrware limitation, or just kernel's USB stack implementation (which, IMHO, is quite flaky and ugly anyway) that's at fault. UFS without softupdates give write performance (while copying /boot/kernel) of a few kilobytes/s (well, maybe few hundred, if it feels like it). Short answer: don't waste your money. Small 46 mm hard drives are better (but not completely noiseless). [SorAlx] ridin' VN1500-B2