parallel run error on new 12-core machine

Hi All,

LAMMPS does not appear to be able to run in parallel on my new Windows 7 machine. I get the Windows application error “the application was unable to start correctly (07xc00007b)”.

My lab just got a new 64-bit 12-core machine (each processor is hyper-threaded, so that there are a total of 24 virtual processors). I’ve installed the latest versions of MPICH2, and downloaded the latest Windows LAMMPS parallel executable. I’ve enabled smpd and moved the requisite smpd.exe and mpiexec.exe files into the same directory. I use this set up on my older 2-processor 64 bit Windows 7 workstation, but the new 12-core does not work.

On the 12-core I can run “mpiexec –n 2 hostname” as a test in the command prompt with no problem, up to 24 processors, which means the mpi seems to be working fine. I’ve tried the LAMMPS serial on my input script and it works fine.

Any suggestions? Is LAMMPS not compatible with hyper-threading architecture or something to that effect?