Path: csiph.com!goblin2!goblin.stu.neva.ru!newsfeed.xs4all.nl!newsfeed8.news.xs4all.nl!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.004 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'subject:Python': 0.05; 'pypy': 0.07; 'cc:addr:python-list': 0.09; 'received:openend.se': 0.09; 'received:theraft.openend.se': 0.09; 'cc:addr:lac': 0.16; 'cc:addr:openend.se': 0.16; 'from:addr:lac': 0.16; 'from:addr:openend.se': 0.16; 'from:name:laura creighton': 0.16; 'loops': 0.16; 'message-id:@fido.openend.se': 0.16; 'received:89.233': 0.16; 'received:89.233.217': 0.16; 'received:89.233.217.133': 0.16; 'received:fido': 0.16; 'received:fido.openend.se': 0.16; 'said.': 0.16; 'looked': 0.16; 'laura': 0.18; 'runs': 0.18; '2015': 0.20; 'cc:addr:python.org': 0.20; 'aug': 0.20; 'cc:2**1': 0.22; 'seems': 0.23; 'header:In- Reply-To:1': 0.24; 'rest': 0.26; 'fri,': 0.27; '+0200,': 0.27; 'went': 0.28; 'initial': 0.28; 'received:se': 0.29; 'cc:no real name:2**1': 0.29; 'code': 0.30; 'up.': 0.32; 'generally': 0.32; 'reported': 0.32; 'run': 0.33; 'could': 0.35; 'done': 0.35; 'but': 0.36; 'faster': 0.36; 'heard': 0.36; 'subject:: ': 0.37; 'really': 0.37; 'agree': 0.37; 'charset:us-ascii': 0.37; 'seem': 0.37; 'doing': 0.38; 'christian': 0.38; 'thank': 0.38; 'some': 0.40; 'your': 0.60; 'header:Message-Id:1': 0.61; 'skip:n 10': 0.62; 'times': 0.63; 'between': 0.65; 'received:89': 0.80; '>of': 0.84; 'exceeding': 0.84; 'gollwitzer': 0.84; 'taught': 0.97 To: Christian Gollwitzer cc: python-list@python.org, lac@openend.se From: Laura Creighton Subject: Re: Python speed In-Reply-To: Message from Christian Gollwitzer of "Fri, 07 Aug 2015 23:26:46 +0200." References: <2261c8c6-77ba-453d-9205-0a922fa67c81@googlegroups.com><04b7cdd0-1eb0-4378-9d14-38e97b4456a7@googlegroups.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <30239.1438984913.1@fido> Date: Sat, 08 Aug 2015 00:01:53 +0200 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.3.9 (theraft.openend.se [89.233.217.130]); Sat, 08 Aug 2015 00:01:58 +0200 (CEST) X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.20+ Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 27 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1438984926 news.xs4all.nl 2929 [2001:888:2000:d::a6]:46584 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:95143 In a message of Fri, 07 Aug 2015 23:26:46 +0200, Christian Gollwitzer writes: >Am 07.08.2015 um 19:17 schrieb Laura Creighton: >> you >> really only are doing crunching, and your crunching is done >> in loops which run for a significant amount of time -- then PyPy >> is generally faster than Fortran. > >PyPy faster than Fortran in a tight number-crunching loop? Sorry I find >this very hard to believe. I could accept that PyPy can match the speed >of Fortran in these cases, but exceeding seems highly unlikely. Was it a >mistake, or do you have a reference that shows how PyPy can be faster >than Fortran? > >I agree with the rest what you have said. > > Christian My apologies -- I went and looked it up, and it seems that the person who reported this got taught how to vectorise his Fortran code and some other tricks, and now his Fortran code runs between 2.5 and 3 times faster than PyPy for his numberical benchmarks. I seem to have got the initial news, and never heard about the correction .... Thank you for bringing this up. Laura