Concur! Porting code to BGL was more or less trivial. "porting" to CUDA means basically re-imagining how to parallelize your code.
On Thu, Apr 4, 2013 at 8:22 AM, Prentice Bisbal <prentice.bis...@rutgers.edu > wrote: > On 04/03/2013 11:42 AM, Geoffrey Jacobs wrote: > > On 04/03/2013 08:27 AM, Bret Stouder wrote: > >> Prentice: > >> > >> For the money you could buy a lot more real computational cycles that > last a lot longer than anything proprietary from IBM. The reason the > Origins have been out of production for a long time is the result of > research moving to a commodity server platform. Taken a look at what Cray > offers lately? Looks a lot like commodity. If you are going to take the > time to port code, it seems that a reasonable argument could be made to > stay away from Blue Gene and port to Cuda or Phi. > >> > >> Bret > > Actually, that's a naive argument. The Blue Gene architecture uses > standard MPI and support C, C++, Fortran, and Python, so any MPI > compliant program written in any of those languages, which will also run > just fine on a Blue Gene, with no porting necessary - just compile the > code for the BG processors using GCC or the IBM XL compilers. IBM > provides the ESSL and MASSV libaries that are optimized for the Blue > Gene, but those are specified at link time, so I wouldn't really call > that porting. Sure, there are tweaks you could use to really optimize > your code for BG, but just doing the above will get you very far. > > In contrast, Cuda requires adding Cuda specific code to move data into > and out of the device, and the sections to be run on the cuda processors > needs to be rewritten in terms of cuda thread index, etc. > > For a large code, this could take a significant amount of labor, enough > that it's conceivable in certain cases buying a Blue Gene could be > quicker and more cost-effective than spending all the money on the labor > to port your code to Cuda, test, optimize, test... > > In short, it's a lot more effort to port MPI-compliant code for Cuda > than for a Blue Gene. > > I specifically didn't mention Phi because I do not know the details of > porting/optimizing code for Phi. > > Prentice > > _______________________________________________ > 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 > -- - - - - - - - - - - - - - - - - - - - - - Nathan Moore Winona, MN - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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