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 TyUlZclg4F7d for ; Mon, 23 Jul 2012 10:14:08 +0200 (CEST) Received: from v4.tansi.org (ns.km33513-03.keymachine.de [87.118.94.3]) by mail.saout.de (Postfix) with ESMTP for ; Mon, 23 Jul 2012 10:14:08 +0200 (CEST) Received: from gatewagner.dyndns.org (84-72-142-78.dclient.hispeed.ch [84.72.142.78]) by v4.tansi.org (Postfix) with ESMTPA id 17BBD20595B for ; Mon, 23 Jul 2012 10:14:08 +0200 (CEST) Date: Mon, 23 Jul 2012 10:14:07 +0200 From: Arno Wagner Message-ID: <20120723081407.GA872@tansi.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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120723062850.GA6931@merlins.org> 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: dm-crypt@saout.de On Sun, Jul 22, 2012 at 11:28:51PM -0700, Marc MERLIN wrote: > On Sun, Jul 22, 2012 at 11:47:57PM +0200, Arno Wagner wrote: > > On Sun, Jul 22, 2012 at 01:39:29PM -0700, Marc MERLIN wrote: > > > On Sun, Jul 22, 2012 at 09:47:32PM +0200, Yves-Alexis Perez wrote: > > > > > Any suggestions would be appreciated. > > > > > > > > I'm using Debian sid (so still at 3.2 kernel), currently using a 256G > > > > Samsung SSD. What I get is: > > > > SID? That would be "unstable", whit possible assorted problems. Ok, sorry for my confusion, what kernel/distro are you running? [...] > > Maybe AES-NI needs very long for something it needs to do each > > sector. Google("aes-ni slow") found at least some indications that > > aes-ni may still have problems. > > It was worth a shot, thanks for the suggestion. > > gandalfthegreat:~# lsmod | grep aes > aes_x86_64 16796 34 > gandalfthegreat:~# hdparm -t -T /dev/mapper/cryptroot > > /dev/mapper/cryptroot: > Timing cached reads: 15802 MB in 2.00 seconds = 7909.98 MB/sec > Timing buffered disk reads: 68 MB in 3.04 seconds = 22.39 MB/sec > gandalfthegreat:~# > > Unfortunately, speed is exactly the same. > > with aes_x86_64: > gandalfthegreat:/var/local/VirtualBox VMs/w2k_virtual# dd if=test of=/dev/null > 4192640+0 records in > 4192640+0 records out > 2146631680 bytes (2.1 GB) copied, 12.4848 s, 172 MB/s > > I then rebooted with aesni_intel and got this: > gandalfthegreat:/var/local/VirtualBox VMs/w2k_virtual# dd if=test of=/dev/null > 4192640+0 records in > 4192640+0 records out > 2146631680 bytes (2.1 GB) copied, 8.42506 s, 255 MB/s That does not seem to be it. > So those speeds are expected/believable, but I still don't know why > hdparm is so slow on /dev/mapper/cryptroot. > > Mmmh.... Indeed. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., Email: arno@wagner.name GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision. -- Bertrand Russell