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 1QrZPB-0000Z5-8c for garchives@archives.gentoo.org; Thu, 11 Aug 2011 17:50:53 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 245B721C1D3; Thu, 11 Aug 2011 17:50:43 +0000 (UTC) Received: from mail-fx0-f53.google.com (mail-fx0-f53.google.com [209.85.161.53]) by pigeon.gentoo.org (Postfix) with ESMTP id E616D21C12C for ; Thu, 11 Aug 2011 17:49:24 +0000 (UTC) Received: by fxd23 with SMTP id 23so2390019fxd.40 for ; Thu, 11 Aug 2011 10:49:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=from:to:subject:date:message-id:user-agent:in-reply-to:references :mime-version:content-transfer-encoding:content-type; bh=8T7G35e4flNufuPGmsnDuxClFDCLzBOakvsT8YjtU8Y=; b=ClFl3jFowAgH4NZETl0o2pnFbKlOPcVY6gFc3JOMQg+zg+Dgxep+n4gQ8pXm9EYjIy SdfiwZjb3DUbGCrpPe5sclwJtnxJGlpsUaIBqwbBUX0gdhANhOrTnhn1wRVmJchH68HZ /AdoFWCjKbVjpQghbRObRspkH0hf1Z2I74bzc= Received: by 10.223.55.209 with SMTP id v17mr3705636fag.77.1313084964137; Thu, 11 Aug 2011 10:49:24 -0700 (PDT) Received: from localhost.localnet (p4FC743BE.dip0.t-ipconnect.de [79.199.67.190]) by mx.google.com with ESMTPS id q15sm1734242fah.32.2011.08.11.10.49.22 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 11 Aug 2011 10:49:23 -0700 (PDT) From: Volker Armin Hemmann To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] {OT} USB 3.0 hard drive speed test Date: Thu, 11 Aug 2011 19:49:21 +0200 Message-ID: <1482551.25fYdY8kaD@localhost> User-Agent: KMail/4.7.0 (Linux/3.0.1; KDE/4.7.0; x86_64; ; ) In-Reply-To: References: 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-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Archives-Salt: X-Archives-Hash: ba3f15806b6f3ce9b5893416341ef958 Am Donnerstag 11 August 2011, 10:30:04 schrieb Mark Knecht: > On Thu, Aug 11, 2011 at 10:12 AM, Grant wrote: > > I'm testing this USB 3.0 bus-powered hard drive: > > > > http://www.amazon.com/gp/product/B0041OSQ9S > > > > and I get: > > > > # hdparm -tT /dev/sdb > > /dev/sdb: > > Timing cached reads: 8006 MB in 2.00 seconds = 4004.33 MB/sec > > Timing buffered disk reads: 252 MB in 3.01 seconds = 83.63 MB/sec > > > > # hdparm -tT /dev/sdb > > /dev/sdb: > > Timing cached reads: 8230 MB in 2.00 seconds = 4116.54 MB/sec > > Timing buffered disk reads: 252 MB in 3.02 seconds = 83.55 MB/sec > > > > # hdparm -tT /dev/sdb > > /dev/sdb: > > Timing cached reads: 8446 MB in 2.00 seconds = 4224.36 MB/sec > > Timing buffered disk reads: 230 MB in 3.02 seconds = 76.28 MB/sec > > > > Wikipedia says USB 3.0 has transmission speeds of up to 5 Gbit/s. > > Doesn't MB/sec denote mega*bytes* per second? > > > > - Grant > > 4000MB/s = 4Gb/s please read man hdparm -T Perform timings of cache reads for benchmark and comparison purposes. For meaningful results, this operation should be repeated 2-3 times on an otherwise inactive system (no other active processes) with at least a couple of megabytes of free memory. This displays the speed of reading directly from the Linux buffer cache without disk access. This measurement is essentially an indication of the throughput of the processor, cache, and mem- ory of the system under test. as you can see, those numbers have nothing to do with the transport. And 80mb/sec for a harddisk is really, really good. -- #163933