Xref: utzoo comp.sys.intel:1287 comp.sys.m88k:239 Path: utzoo!utgpu!watserv1!watmath!att!rutgers!njin!princeton!gauss!markv From: markv@gauss.Princeton.EDU (Mark VandeWettering) Newsgroups: comp.sys.intel,comp.sys.m88k Subject: Re: Processors for parallel architectures? Keywords: Request for comments and/or recommendations Message-ID: <1146@idunno.Princeton.EDU> Date: 10 Jul 90 19:59:44 GMT References: <609@dg.dg.com> Sender: news@idunno.Princeton.EDU Reply-To: markv@gauss.Princeton.EDU (Mark VandeWettering) Followup-To: comp.sys.intel Distribution: na Organization: Princeton University Lines: 28 In article <609@dg.dg.com> uunet!dg!chan (Allen Chan) writes: >the i860 does not have hardware that keeps caches coherent >in a multiprocessor system. the m88k does have snoop logic >that does this. in my opinion, you should not even try to >build a parallel/multi processor system with the i860. > >disclaimer: "i speak only for myself" Well, I almost agree, but then again, not all parallel machines have to share memory, in which case your cache strategy is kind of moot. The i860 is not a real elegant chip. As one who has immersed himself in the bowels of i860 assembly language, I can say with great conviction that it isn't the most fun thing I have ever done. Because compilers are not able to use the chip effectively yet, the chip itself is an incredible time sink. But, for all its foibles, it does go really fast for carefully coded programs. Like REALLY fast. You have an fft you want done, hey, the i860 will blast it out at a screaming 40 megaflops, double precision. The 88K, MIPS R3000, or whathaveyou just ain't that fast. Someday (hopefully soon) real compilers will be available that will make this chip really fun and fast to use. Till then, it may not be the easiest, but it certainly gives an enormous performance for relatively little cost. Mark