PB is a set of programs that will instrument a code, and then create timing and performance files during run time. There are other scripts for analysis of the data. PB is a useful tool for both analyzing code, and for performance predictions of new machines. For analyzing code, PB can be used to get information about each subroutine and the time and flops required. This tool was developed by Instrumental (www.instrumental.com) and is currently unsupported. Installation instructions can be found at http://icl.cs.utk.edu/projects/papi/tools/PBINSTALL and more information about PB can be found at http://icl.cs.utk.edu/projects/papi/tools/PBREADME.