[gmx-users] how to optimize performance of IBM Power 775?

[Albert]

Dear:

   Our institute got a  IBM Power 775 cluster and it claimed to be very 
good. However, it doesn't support g_tune_pme. I use the following script 
for job submission:



#@ job_name = gromacs_job
#@ output = gromacs.out
#@ error = gromacs.err
#@ class = kdm
#@ node = 4
#@ tasks_per_node = 32
#@ wall_clock_limit = 01:00:00
#@ network.MPI = sn_all,not_shared,US,HIGH
#@ notification = never
#@ environment = COPY_ALL
#@ job_type = parallel
#@ queue
mpiexec -n 128 /opt/gromacs/4.5.5/bin/mdrun -nosum -dlb yes -v -s md.tpr

it is only 7 ns/day.

However, in another cluster with the same system, Core number and 
parameters, I can get up to 30 ns/day.

Does anybody have any advices for this issue?

thank you very much
Albert