Larrabee delayed: anyone know what's happening?
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From: Robert Myers on 3 Jan 2010 02:55 On Jan 2, 11:57 pm, EricP <ThatWouldBeTell...(a)thevillage.com> wrote: > Andrew Reilly wrote: > > > I have occasionally wondered just how many "interesting" problems fit > > that model. Certainly some classes of search or optimization, but many > > that use real or interesting data? > > Protein folding distributed computing > to understand protein folding, misfolding, and related diseaseshttp://folding.stanford.edu/ > There are some problems with this approach that I think I similar to the problems in incompressible fluid mechanics. The coulomb field is a long-range field and the interesting dynamics are in collective behavior that results from lots of local details. While the distributed computing types undoubtedly have some defensible logic, I'm skeptical. One of those many things I'd dig into if I had the time. I don't see how you can do this problem with massive global communication. If you approximate away that need, you may be approximating away the physics, just as you do in fluid mechanics. Robert.
From: Mayan Moudgill on 3 Jan 2010 02:59 Andrew Reilly wrote: > On Sat, 02 Jan 2010 19:13:57 -0800, Robert Myers wrote: > > >>It's conceivable that I could find a >>combination of @Home settings and Computer Power Management setting that >>would result in negligible extra power, but how many will do that? > > > I'm fairly confident that Mayan's use of @Home as a tag was more along > the lines of "computations that are known to require lots of grinding on > small chunks of data, and so therefore trivially parallelizable with > arbitrary network geometry", rather than the "free cycles" aspect. > Precisely! Robert has a (probably legitimate) persistent complaint about the inability to solve certain classes of physics problems because of computational resources. So: are the physics problems that are being tackled on a BlueGene-style supercomputer at LLNL do-able on a CoW/NoW? If not, what makes it possible to do it only on a BlueGene-style machine? [Robert also claims that the results based on access to supercomputers are externally unverifiable, suspect, and possibly incorrect. The first may be true, and the rest do follow as conclusions. However, I'm not interested in tackling that subject. I just mention it so that anyone who doesn't want to address the technical question can have something to quote when they post a response.]
From: Rob Warnock on 3 Jan 2010 05:57 Robert Myers <rbmyersusa(a)gmail.com> wrote: +--------------- | rpw3(a)rpw3.org (Rob Warnock) wrote: | > Robert Myers �<rbmyers...(a)gmail.com> wrote: | > +--------------- | > | I doubt if operating systems will ever be written in an elegant, | > | transparent, programmer-friendly language. | > +--------------- | > | > So the various Lisp Machines never existed? ;-} ;-} | > Oh, wait: | > http://en.wikipedia.org/wiki/Lisp_Machine .... | Even though I know some lisp true-believers, I know nothing about | using it for actual computig. Does a lisp operating system have any | purpose other than to say you did it, or to run the small number of | computers that have been built specifically for lisp? +--------------- You answered that question *in* your original question: The purpose is to have an operating system written in an elegant, transparent, programmer-friendly language!! ;-} +--------------- | I mean, if I wanted to badly enough, I could build some fairly interesting | structures out of popsicle sticks, but what would I have accomplished? +--------------- Nothing, unless you beat this guy: ;-} ;-} http://www.worldrecordsacademy.org/biggest/tallest_Popsicle_stick_structure_Stephen_Guman_sets_world_record_90456.htm But the Lisp-based operating system users got systems that were easy to understand, maintain, and extend [well, for Lispers]... -Rob ----- Rob Warnock <rpw3(a)rpw3.org> 627 26th Avenue <URL:http://rpw3.org/> San Mateo, CA 94403 (650)572-2607
From: Rob Warnock on 3 Jan 2010 06:00 Mayan Moudgill <mayan(a)bestweb.net> wrote: +--------------- | Rob Warnock wrote: | > Robert Myers <rbmyersusa(a)gmail.com> wrote: | > +--------------- | > | I doubt if operating systems will ever be written in an elegant, | > | transparent, programmer-friendly language. | > +--------------- | > | > So the various Lisp Machines never existed? ;-} ;-} | | Exactly how is LISP elegant, transparent & programmer-friendly? +--------------- See <http://www.paulgraham.com/avg.html>... -Rob ----- Rob Warnock <rpw3(a)rpw3.org> 627 26th Avenue <URL:http://rpw3.org/> San Mateo, CA 94403 (650)572-2607
From: nmm1 on 3 Jan 2010 06:15
In article <7qalq0F2icU1(a)mid.individual.net>, Andrew Reilly <areilly---(a)bigpond.net.au> wrote: > >I'm fairly confident that Mayan's use of @Home as a tag was more along >the lines of "computations that are known to require lots of grinding on >small chunks of data, and so therefore trivially parallelizable with >arbitrary network geometry", rather than the "free cycles" aspect. > >I have occasionally wondered just how many "interesting" problems fit >that model. Certainly some classes of search or optimization, but many >that use real or interesting data? Yes. Quite a lot. In addition to global search/optimisation, there is the whole class of Monte-Carlo algorithms. >Part of this discussion that I find particularly interesting is the >distinction between "arbitrarily scalable" code (if such exists) and code >that potentially has a largish but problem-specific "right" number of >nodes. I'm fairly sure that most of the problems that I find interesting >are in the latter camp: past a certain point structuring the code to make >use of more processors would require at least a completely different >approach to decomposition, if it is possible at all. Arbitrarily scalable code certainly exists, but often has the property that there is a maximum effective number of nodes for each data size. There is also the question of how fundamental the constraints are. In some cases, problems are inherently unscalable but, in most, it is not known whether they are or not. Regards, Nick Maclaren. |