I've tried compiling 3.2.1 with HDF5_ENABLE_PARALLEL on and off. When on the XDMF reader just runs and runs, eating CPU time. When off things work well. The XDMF file uses 8 HDF files and I used 2 processors. Its a CENTOS 5 system with MPICH2 from Argonne. Has anyone else tried "parallel" HDF5? Kent Pittsburgh Supercomputing Center