I take back one thing I mentioned in my talk in Atlanta. I think I said that Lustre striping does not really influence the read performance. With my latest results in hand, I must point out this is not true. I might have been confused by some former Piz Daint Lustre performance issues and/or HDF5 library issues I mentioned.
Here are my latest slides from PASC19. https://polybox.ethz.ch/index.php/s/PPZLSyZOKo3UXPS On slide 18, there is some comparison for different stripe settings. I can now see a speed-up of ~4 for 1 vs 12 stripes (which is actually the number of cores per node) for the mesh with 128M elements. The times are very similar for 8 and 64 computation nodes. Toby, could you maybe forward this message to the meeting attendees? I don't want to leave anybody confused. Thanks, Vaclav
