From: Peter Wu Subject: aes-x86_64 seems slower than the generic implementation Date: Sat, 19 Apr 2014 16:42:07 +0200 Message-ID: <2046035.alMyLlD0ki@al> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: Herbert Xu , "David S. Miller" , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Andreas Steinmetz To: linux-crypto@vger.kernel.org Return-path: Received: from lekensteyn.nl ([178.21.112.251]:41691 "EHLO lekensteyn.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751059AbaDSOmN (ORCPT ); Sat, 19 Apr 2014 10:42:13 -0400 Sender: linux-crypto-owner@vger.kernel.org List-ID: Hi! When comparing the x86_64 assembly implementation (module aes-x86_64) against the generic AES implementation, I found that the generic implementation was consistenly faster. Test setup #1: * cryptsetup 1.6.4 * Linux v3.15-rc1-356-gebfc45e, https://github.com/Lekensteyn/aur/blob/1d1950/linux-custom/config * CPU: Intel i5-460M * Distro: Arch Linux x86_64 Command: for i in {0..10};do cryptsetup benchmark --cipher aes-xts; done Test results for n=11, mean (+ standard deviation), enc/dec: * aes-x86_64: 139.6 (0.68) / 138.5 (0.22) * aes-generic: 144.8 (0.63) / 144.6 (0.31) About a month ago, I conducted a similar test on a different machine[1]. * cryptsetup 1.6.4 * QEMU: 1.7.0 * Linux (guest, no modules): v3.14-rc7-59-g08edb33 * Linux (host): v3.14-rc5 * CPU: Intel i7-3770 Test results comparing aes-generic, aes-x86_64 and AESNI (n=3): generic x86_64 aesni * aes-cbc-128 201/276 200/280 669/2500 * aes-cbc-256 162/205 159/208 492/1835 * aes-xts-256 275/270 272/276 2050/2034 (note, AES-NI performance varies a lot) Aren't the assembly implementations supposed to be faster? Kind regards, Peter [1]: https://lekensteyn.nl/files/linux-crypto-benchmark/