We can keep use  all features of C++11. Maybe IBM will release a new version this year. Anyway,  we can test ogs6 on EVE and maybe possible on the new super computer at Dresden, if it is not IBM machine.  @rinkk The difference the calculations is not about the number of nodes. The test have 4 million elements, on EVE, the speedup monotonically  increases along with the number of compute cores until around 300, while on JUQUEEN that core number is over 500.