[gmx-users] Extension on different machines (CPU/GPU

[Nicolas Cheron]

Dear all,

I ran a 250ns simulation with Gromacs 5.1.2 on a machine with only CPUs. I
then wanted to extend the simulation to 300ns, and copied the .tpr and the
.cpt to another machine with GPUs (also running Gromacs 5.1.2). I observed
strange results, so I decided to also extend the simulation (from 250ns) on
the first machine to compare.

Different results are obtained for the 2 extensions (that were started from
the same .tpr and .cpt) on the 2 different machines/architectures. Is it a
known behaviour, and one should never proceed like this? Is it due to
CPU/GPU, or only the fact that machines are different and the same would
have happened on another CPU machine?

Thank you

Nicolas

PS: I am looking at a solute in a water:glycerol mixture. By "different
results" I mean that the number of water (or glycerol) around the solute
are different at all time steps