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

[Carsten Kutzner]

Hi,

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?

   Carsten


---------------------------------------------------
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
http://www.gwdg.de/~ckutzne