Xref: utzoo comp.lang.fortran:910 comp.unix.questions:8211 Path: utzoo!attcan!uunet!yale!cmcl2!phri!roy From: roy@phri.UUCP (Roy Smith) Newsgroups: comp.lang.fortran,comp.unix.questions Subject: Re: Sun 3 vs uVAXII floating point speed.... Message-ID: <3381@phri.UUCP> Date: 14 Jul 88 12:45:10 GMT References: <25065@ucbvax.BERKELEY.EDU> Reply-To: roy@phri.UUCP (Roy Smith) Distribution: na Organization: Public Health Research Inst. (NY, NY) Lines: 29 ao@cevax.berkeley.edu (Akin Ozselcuk) writes: > I am posting this article on behalf of a friend of mine who is planning > to buy either a Sun3 or a VAX Station 2000 (a watered down uVAXII). He > is planning to do a lot of number crunching by using f77. Asking if a uVAX or a Sun-3 is faster for floating point is a misleading question, or at least an imcomplete one. Are you talking about a 3/50 without even the 68881 option or a 3/260 with FPA? The difference in floating point speed between the two is at least an order of magnitude. By way of comparison, we have an 11/750 with FPA, 3/50s both with and without 68881s and 3/160s with FPAs. To give you some feel for the rough relative speeds (notice the use of lots of ambigiuating terms; you're mileage will vary depending on zillions of factors), we find that a 3/50 with 68881 and the 750 with FPA are roughly the same speed. A 3/160 with FPA is about 10 times faster than that. From what I understand, the 3/260 (which we don't have) uses exactly the same FPA board as the 160 so for floating-point intensive applications, the 260 is not a whole lot faster than the 160. My guess is that the uVAX-II is about the same speed as a 750. Another factor to consider is that Sun's new snazzy Fortran compiler is supposed to produce *much* faster code than the generic Unix f77 compiler. -- Roy Smith, System Administrator Public Health Research Institute {allegra,philabs,cmcl2,rutgers}!phri!roy -or- phri!roy@uunet.uu.net "The connector is the network"