On Apr 5, 2011, at 7:22 AM, Greg Lindahl wrote: > On Mon, Apr 04, 2011 at 09:54:37AM -0700, Massimiliano Fatica wrote: > >> If you are old enough to remember the time when the first distribute >> computers appeared on the scene, >> this is a deja-vu. > > Not to mention the prior appearance of array processors. Oil+Gas > bought a lot of those, too. Some important radio astronomy data > reduction algorithms were coded for them -- a VAX 11/780+FPS AP120B > was 10X faster than the VAX by itself. Then microprocessor-based > workstations arrived, and the game was over, ease of use FTW. > >> Even on a single system, if you try an auto-parallel/auto-vectorizing >> compiler on a real code, your results will probably be disappointing. > > The wins from such compilers have been steadily decreasing, as main > memory gets farther and farther away from the CPU and caches. > > -- greg
It's different this time indeed; classic cpu's will never again deliver big performance. cache - coherency is simply too complicated with many cores. cpu's also will need a manycore co-processor therefore. furthermore manycores simply are cheaper to produce and they can eat a bigger powerbudget. 3 very powerful arguments which regrettably limits cpu's, but that's the price we pay for progress. It won't mean cpu's will go away of course any soon, they're so generic and easy to program that they will survive. Just offload the calculations to the manycores. please don't estimate the argument of cheaper to produce. > > > _______________________________________________ > Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin > Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
