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 1PgYXm-0005vq-5R for garchives@archives.gentoo.org; Sat, 22 Jan 2011 08:09:58 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 80053E0ABE; Sat, 22 Jan 2011 08:08:35 +0000 (UTC) Received: from smtp.gentoo.org (smtp.gentoo.org [140.211.166.183]) by pigeon.gentoo.org (Postfix) with ESMTP id 5161AE0ABE for ; Sat, 22 Jan 2011 08:08:35 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp.gentoo.org (Postfix) with ESMTP id D6E591B4080 for ; Sat, 22 Jan 2011 08:08:34 +0000 (UTC) X-Virus-Scanned: by amavisd-new using ClamAV at gentoo.org X-Spam-Score: -2.876 X-Spam-Level: X-Spam-Status: No, score=-2.876 required=5.5 tests=[AWL=-0.277, BAYES_00=-2.599] 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 ALRSbu70ZYOD for ; Sat, 22 Jan 2011 08:08:28 +0000 (UTC) Received: from lo.gmane.org (lo.gmane.org [80.91.229.12]) by smtp.gentoo.org (Postfix) with ESMTP id 47B921B4017 for ; Sat, 22 Jan 2011 08:08:25 +0000 (UTC) Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1PgYWF-0005tP-3G for gentoo-user@gentoo.org; Sat, 22 Jan 2011 09:08:23 +0100 Received: from athedsl-393122.home.otenet.gr ([79.131.87.160]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 22 Jan 2011 09:08:23 +0100 Received: from realnc by athedsl-393122.home.otenet.gr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 22 Jan 2011 09:08:23 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: gentoo-user@lists.gentoo.org From: Nikos Chantziaras Subject: [gentoo-user] Re: AHCI/IDE-question Date: Sat, 22 Jan 2011 10:08:23 +0200 Organization: Lucas Barks Message-ID: References: <20110121184507.GC5787@solfire> <20110121201150.GC5878@solfire> <4D39EE7D.6070603@gmail.com> <201101220006.02377.alan.mckinnon@gmail.com> <4D3A0929.6080606@gmail.com> <4D3A8C30.9050201@gmail.com> 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=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: athedsl-393122.home.otenet.gr User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20110103 Thunderbird/3.1.7 In-Reply-To: <4D3A8C30.9050201@gmail.com> X-Archives-Salt: X-Archives-Hash: 60f629197bdac9aad24936fbb42070b8 On 01/22/2011 09:50 AM, Dale wrote: > Nikos Chantziaras wrote: >> On 01/22/2011 12:31 AM, Dale wrote: >>> [...] >>> And I thought there was something weird with me on this one. o_O I did >>> switch it back to AHCI after I got done booting the CD thingy. I really >>> can't tell any difference in speed between the two and neither could >>> hdparm -tT either. >> >> hdparm measures raw throughput when reading continuously from one >> position to another. AHCI improves performance when the disk needs to >> read from several different places, which is the case in every day >> use. It does this by providing a feature similar to what SCSI >> provides: native command queuing (NCQ). You can read about what this >> is and why we want it here: >> >> http://en.wikipedia.org/wiki/Native_Command_Queuing > > Other than copying a file and using time to measure how long it takes, > what is the best test of a hard drive's speed? By running a benchmark tool that does exactly this. IOzone is a nice one: http://www.iozone.org It's in portage: "app-benchmarks/iozone". > Also, does or can the kernel override the BIOS setting? I think it uses > AHCI no matter what is in the BIOS. It seems it would be at least some > difference in speed. The kernel can't change this setting and has no access to it whatsoever.