[gmx-users] grompp -np option

[Nathan Moore]

Is the limit of -np to no more that 256 hard-coded into grompp for a
specific reason?  Is it a simple change to the code (I havn't looked)?

More generally, is there much understanding of the "optimum" number of
atoms each node should have for peak performance in a parallel job?  eg if
I have two systems, one with 5,000 atoms, and another with 500,000 atoms,
would they both be split up into blocks of 1000 atoms/compute node for
optimum (minimum real time) performace?

regards,

NT Moore