From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.saout.de ([127.0.0.1]) by localhost (mail.saout.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wtIz7aHnM9LY for ; Mon, 23 Jul 2012 19:54:27 +0200 (CEST) Received: from mail1.merlins.org (magic.merlins.org [209.81.13.136]) (using TLSv1.2 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.saout.de (Postfix) with ESMTPS for ; Mon, 23 Jul 2012 19:54:27 +0200 (CEST) Date: Mon, 23 Jul 2012 10:54:23 -0700 From: Marc MERLIN Message-ID: <20120723175423.GB15867@merlins.org> References: <20120722190757.GB10089@merlins.org> <20120722202213.GA7306@fancy-poultry.org> <20120722190757.GB10089@merlins.org> <1342986452.26887.3.camel@scapa> <20120722203929.GB3925@merlins.org> <20120722214757.GA16793@tansi.org> <20120723062850.GA6931@merlins.org> <20120723081407.GA872@tansi.org> <20120723161242.GB27727@merlins.org> <1343060350.26887.20.camel@scapa> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: <500D8993.7030802@andregall.de> <1343060350.26887.20.camel@scapa> Subject: Re: [dm-crypt] aes-xts-plain with aes_x86_64 makes my SSD 5x slower than my encrypted HD List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yves-Alexis Perez , =?iso-8859-1?Q?Andr=E9?= Gall Cc: dm-crypt@saout.de On Mon, Jul 23, 2012 at 06:19:10PM +0200, Yves-Alexis Perez wrote: > > I'll try rebuilding a non preempt kernel just in case. >=20 > Maybe try with Debian kernel first? It's just an apt-get install away > and will give you a setup identical as mine. I have a custom initramfs, it was easier to compile a new kernel than to try and get the debian one to boot my system :) But for reference, what kernel package are you using? On Mon, Jul 23, 2012 at 07:27:47PM +0200, Andr=E9 Gall wrote: > I remember a test which I conducted after I received my Intel SDD 510=20 > 120 GB about 1 year ago. I don't remember all the details, but the=20 > essence was that write speed decreased dramatically if the write process = > wasn't aligned. =20 > I did: > dd if=3D/dev/zero of=3D/dev/sda bs=3D4k > I got around 400 Mb/sec, which was expected. But when I did: >=20 > dd if=3D/dev/zero of=3D/dev/sda bs=3D5k > I got only around 40 Mb/sec Yes, write alignment and write amplification are definitely issues on SSDs, but note how I was only doing read tests :) See http://www.void.gr/kargig/blog/2012/01/11/linux-ssd-partition-alignment-tip= s/ Cheers, Marc --=20 "A mouse is a device used to point at the xterm you want to type in" - A.S.= R. Microsoft is to operating systems .... .... what McDonalds is to gourmet coo= king Home page: http://marc.merlins.org/ =20