On Thursday 10 July 2008 14:44:25 Peng Zang wrote: > On Thursday 10 July 2008 01:57:44 am J C wrote: > > I know that Caml team wanted to see if many-core shared-memory systems > > were going to stick around before bothering with Caml development that > > takes advantage of them. > > > > Well, it looks like they are here to stay, after all: > > > > http://news.cnet.com/8301-13924_3-9981760-64.html > > This article doesn't say anything about whether the many-core system will > be shared-memory. Remember, a shared memory architecture has to deal with > cache and memory coherence. The prevailing view is that the overhead for > such an approach does not scale. For massively parallel computation we > must turn to message passing or barrier/sync paradigms. > > I am doubtful that a thousand core machine will be shared-memory based.
Today's biggest shared-memory supercomputers already have thousands of cores. > Also, this is a CNET article.. not exactly known for being in depth or well > researched and this article is no exception. It is an article based > entirely on a few speculative comments of some Intel guys. I wouldn't take > it too seriously. > > Personally, I can see why the Caml development team opted not to put effort > into dealing with shared-memory systems. The OCaml development team put huge effort into their concurrent run-time. > It is a stop-gap solution... That is not true. Many-core machines will always be decomposed into shared-memory clusters of as many cores as possible because shared memory parallelism will always be orders of magnitude more efficient than distributed parallelism. OCaml is already ~8x slower than F# on today's eight core desktops. If OCaml's shortcomings are not remedied then it will become exponentially slower than parallelized languages like F# over the next few years until we reach the limit of shared memory parallelism in ~10 years time. Consequently, the parallel GC scheduled for this summer will be the single most important development in OCaml world ever. -- Dr Jon D Harrop, Flying Frog Consultancy Ltd. http://www.ffconsultancy.com/products/?e _______________________________________________ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
