[gmx-users] MPICH on Gbit with > 4 CPUs?

Carsten Kutzner ckutzne at gwdg.de
Fri Oct 14 10:17:30 CEST 2005


has anybody ever managed to run gromacs in parallel on more than 4 CPUs
when using MPICH on Gigabit Ethernet? I have just searched the mailing
lists, where this problem was also reported (but no solution!).

We have dual-CPU Xeons, Linux 2.4. With up to 4 CPUs, gromacs 3.3 and
3.2.1 work. With 5+ CPUs, mdrun initializes properly but never finishes the first
time step. An MPI test program (that does an all-to-all communication)
works happily on up to 40 CPUs with MPICH. With LAM, mdrun works fine
on any number of CPUs as well. Why not with MPICH?


Dr. Carsten Kutzner
Max Planck Institute for Biophysical Chemistry
Theoretical and Computational Biophysics Department
Am Fassberg 11
37077 Goettingen, Germany
Tel. +49-551-2012313, Fax: +49-551-2012302
eMail ckutzne at gwdg.de

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