From owner-freebsd-questions@FreeBSD.ORG Sat Jul 21 16:55:41 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 324C516A418 for ; Sat, 21 Jul 2007 16:55:41 +0000 (UTC) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.freebsd.org (Postfix) with ESMTP id EF50313C461 for ; Sat, 21 Jul 2007 16:55:40 +0000 (UTC) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.14.1/8.13.8) id l6LGtelp047545; Sat, 21 Jul 2007 11:55:40 -0500 (CDT) (envelope-from dan) Date: Sat, 21 Jul 2007 11:55:39 -0500 From: Dan Nelson To: Tim Daneliuk Message-ID: <20070721165539.GA2579@dan.emsphone.com> References: <46A22253.8080100@tundraware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46A22253.8080100@tundraware.com> X-OS: FreeBSD 7.0-CURRENT User-Agent: Mutt/1.5.16 (2007-06-09) Cc: FreeBSD Mailing List Subject: Re: SATA 300 Drive Being Run At 150 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: Sat, 21 Jul 2007 16:55:41 -0000 In the last episode (Jul 21), Tim Daneliuk said: > I asked this question a while back, but needed to do more digging to make > sure I had latest sources etc. > > I have an Intel motherboard that shows this for a SATA controller: > > atapci1: port 0x20c8-0x20cf,0x20ec-0x20ef,0x20c0-0x20c7,0x20e8-0x20eb,0x20a0-0x20af mem 0x90204000-0x902043ff irq 19 at device 31.2 on pci0 > > But the hard drive - a SATA 300 device - shows up like this: > > ad4: 238475MB at ata2-master SATA150 > ^^^^^^^ > Using dd, I have confirmed that the drive is running nowhere near > SATA-III speeds, at least on reads: > > 968470075 bytes transferred in 7.132891 secs (135775249 bytes/sec) What was your dd commandline? If you've got more than 1GB of RAM and tested by reading a file and not the raw device itself, you just tested FreeBSD buffer cache. According to http://www.wdc.com/en/products/productspecs.asp?driveid=135 , that drive's maximum sustained speed is only 93.5 MB/sec, so it doesn't really matter if your interface is running at SATA150 or SATA300 unless you plan on reading exclusively from its 8MB buffer :) -- Dan Nelson dnelson@allantgroup.com