Hi, I did the test with the simple program as shown below. (I use mumps, which is a parallel linear solver.)
This test program does nothing but just calls intialize & finalize routine of MUMPS & MPI. INCLUDE 'mpif.h' INCLUDE 'dmumps_struc.h' TYPE (DMUMPS_STRUC) MUMPS_PAR c MUMPS_PAR%COMM = MPI_COMM_WORLD MUMPS_PAR%SYM = 1 MUMPS_PAR%PAR = 1 MUMPS_PAR%JOB = -1 ! INITIALIZE MUMPS CALL MPI_INIT(IERR) CALL DMUMPS(MUMPS_PAR) c CALL MPI_COMM_RANK( MPI_COMM_WORLD, MYID, IERR ) IF ( MYID .EQ. 0 ) CALL SLEEP(180) ! WAIT 180 SEC. c MUMPS_PAR%JOB = -2 ! FINALIZE MUMPS CALL DMUMPS(MUMPS_PAR) CALL MPI_FINALIZE(IERR) c END command line : mpirun -host node06,node05 -np 16 ./testrun Results: User & System CPUs are quite different between two versions. Waiting processes are counted as USER CPU in openmpi 1.4.2, while they are counted as USER & SYSTEM CPU in openmpi 1.4.3. Something in the MUMPS intialize routine might affect SYSTEM CPU. node06 CPU | node05 CPU openmpi usr sys idl | usr sys idl 1.4.2 88 0 12 | 100 0 0 1.4.3 41 47 12 | 44 56 0 * process id of node06: 0-07 process id of node05: 08-15 ( total 16 process ) * see attacehd file which is a snap shot of GANGLIA. (See attached file: openmpi143.JPG)