From owner-freebsd-current Thu Nov 14 20:56:42 1996 Return-Path: owner-current Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id UAA12532 for current-outgoing; Thu, 14 Nov 1996 20:56:42 -0800 (PST) Received: from waru.life.nthu.edu.tw (waru.life.nthu.edu.tw [140.114.98.107]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id UAA12510 for ; Thu, 14 Nov 1996 20:56:25 -0800 (PST) Received: from waru.life.nthu.edu.tw (waru.life.nthu.edu.tw [140.114.98.107]) by waru.life.nthu.edu.tw (8.7.6/8.7.3) with SMTP id MAA07641 for ; Fri, 15 Nov 1996 12:57:49 +0800 (CST) Date: Fri, 15 Nov 1996 12:57:49 +0800 (CST) From: Frank Chen-Hsiung Chan To: freebsd-current@freebsd.org Subject: fast libm? Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-current@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Our lab is planning to buy some PPro for scientific calculation. We have previously test the performance of a PPro 200 running FreeBSD and another running Linux. The performance in the Linux box is 2 times faster than the FreeBSD box. Through some investigation, we have found that the problem is due to the math library. The Linux libm is optimized for i386 machine, and written in assembly. Whereas FreeBSD libm is written entirely in C. Personally I favor the FreeBSD, but calculation speed is the major concern. I wonder whether there's anyone trying to optimize libm in FreeBSD? I believe this will extend the use of FreeBSD in scientific realms. BTW, if the FPU option in /etc/make.conf is not turned on, the FreeBSD performance will be 9 times slower than Linux (in Math calculations). -- Frank Chen Hsiung Chan | ------------------------------+--------------------------------- Department of Life Science | frankch@waru.life.nthu.edu.tw National Tsing Hua University | http://waru.life.nthu.edu.tw/ Taiwan |