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Has Supercomputing Hit a Brick Wall?
anzha writes "Horst Simon, Deputy Director of Lawrence Berkeley National Laboratory, has stood up at conferences of late and said the unthinkable: supercomputing is hitting a wall and will not build an exaFLOPS HPC system by 2020. This is defined as one that passes linpack with a performance of one exaFLOPS sustained or better. He's even placed money on it. You can read the original presentation here."
moore's law only talks about transistor counts. building a supercomputer means getting thousands of CPUs to cooperate which is a much harder challenge.
Anyone (with a large wallet) can stick an exoflop worth of CPUs in a large room. by 2020 you'll be able to do that with a not so large wallet. but that does not result in a useful exoflop computer
It's a particular nuisance because the speed of light is pretty strictly enforced...
Even if you went full-on-nuts and replaced fiber interconnects with little tubes full of hard vacuum, to squeak out that slight improvement over the speed of light in glass or air, you'll still see latency that meaningfully hinders the cooperation of multi-GHz CPUs and RAM across systems of any nontrivial size.
For loosely coupled problems, that barely matters; but not all problems are loosely coupled.