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Comment by ljdursi | Hacker News Reader

Thanks! I'm probably mischaracterizing Charm++ a bit, because I'm most familiar with it in particle context (OpenAtom, ChaNGa, NAMD). I guess it's probably particularly used in that context just because it's so good with very fine-grained distributions of work units. I'll edit that line in the article.

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Another nitpick: 128 cores equals ~ 4 nodes only if your problem is not bound by memory bandwidth. If it is, 128 cores equals ~ 16 cores, and then the interconnect matters a lot.

Great writeup though. I do think we need to get more people into the mindset that MPI won't be the standard in 10 years, otherwise it will still be the standard in 10 years.

"won't be the standard in 10 years, otherwise it will still be the standard in 10 years." -- nicely said.

(Thanks Andrew Dalke. You remember it after all these years!) Jonathan, actually, even in that set, OpenAtom is not a particle code. Its a quantum chemistry code where each electronic state is represented often by a large 3D array spread over processors.. For more recent examples of representative miniApps, see http://charmplusplus.org/benchmarks/ or our upcoming workshop (sorry for the plug: http://charm.cs.illinois.edu/charmWorkshop

The broader article deserves further though, and I hope to find time to respond. But it is clear that raising the level of abstraction beyond MPI is necessary.

(Indeed I do!)

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