MPI-I/O on Franklin XT4 System at NERSC
Katie Antypas, Andrew Uselton · 2009
Prior to a software upgrade and hardware maintenance on March 17th 2009 on the Frankin Cray XT4 machine at the National Energy Research Scientific Computing (NERSC) Center, MPI-IO shared file performance saw only a small percentage of file-per-processor performance POSIX performance. The March 17th upgrade unintentionally increased I/O performance significantly for a number of applications. This paper shows the performance differences after the maintenance and explores some of the possible explanations for the dramatic improvements.