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by jedbrown
4710 days ago
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Because ScaLAPACK has a cumbersome interface, poor internal design, relies on incorrect premises that affect performance (block cyclic vs. elemental cyclic), and is buggy. In contrast, Elemental is a joy to use and is almost always faster, often by a large margin (see the Elemental paper). Elemental is not a toy project by any means; it is already the basis for a large share of the interesting parallel linear algebra research and is used by many important applications. Jack is currently the best researcher/implementer in the direct linear algebra world. Anyone that knows me knows that I am a critical bastard that does not throw such praise around lightly. |
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1. What granularity to distribute the entries in the matrix is a long and subtle argument which doesn't provide a clear winner for every operation (the current conclusions are different for LU with partial pivoting vs. reduction to tridiagonal form). I would by no means say that the approach used by ScaLAPACK is wrong, but only that it is unnecessarily complex and only one operation purposefully targets the finest granularity case.
2. Again, I appreciate the complement, but I don't think that arguments from authority are valid, nor do I think that one can be the "best". I have a large number of colleagues doing wonderful work, much of which I find extremely impressive.
Also, it would be good to disclose that you're affiliated with the project you were promoting.