Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!udel!nigel.ee.udel.edu!mccalpin From: mccalpin@perelandra.cms.udel.edu (John D. McCalpin) Newsgroups: comp.benchmarks Subject: Re: Don't use bc (was: More issues of benchmarking) Message-ID: Date: 2 Dec 90 13:32:48 GMT References: <122@thinc.UUCP> <5042@taux01.nsc.com> Sender: usenet@ee.udel.edu Organization: College of Marine Studies, U. Del. Lines: 25 Nntp-Posting-Host: perelandra.cms.udel.edu In-reply-to: amos@taux01.nsc.com's message of 1 Dec 90 21:20:17 GMT >>>>> On 1 Dec 90 21:20:17 GMT, amos@taux01.nsc.com (Amos Shapir) said: [.... commenting on the "echo 2^5000/2^5000 | /bin/time bc" benchmark ...] > This benchmark has no validity! Amos> Sure it doesn't; I wonder how no one else noted this yet: "bc" Amos> is probably the worst choice of a utility to benchmark by. On Amos> most UNIX systems, it just parses expressions, and forks "dc" to Amos> execute them [...] Of course the biggest problem is that almost no one actually *uses* `bc' for any large amount of computation, so no vendor has any incentive to optimize its performance. A secondary problem is that one could trivially optimize the benchmark away by adding a constant-expression simplifier to `bc' before it calls `dc', but everyone already knew that.... (Maple evaluated the expression on my SGI 4D/25 in 0.4 seconds wall time). -- John D. McCalpin mccalpin@perelandra.cms.udel.edu Assistant Professor mccalpin@brahms.udel.edu College of Marine Studies, U. Del. J.MCCALPIN/OMNET Brought to you by Super Global Mega Corp .com