Many users of Von Neumann, Eagle, and Newton, the Cray supercomputers at the NAS Facility, now have accounts on the SGI Origin2000 machines. Since the Crays and Origin2000s have vastly different hardware architectures and the default binary files generated by Fortran programs on these two systems are not interchangeable, porting codes and data from one architecture to the other becomes a non-trivial problem.
Users have two major choices.
They can either convert Cray binary files to SGI binary files by running a program on the Cray, or they can do the conversion on the Origin2000. Doing the conversion on the Cray is fairly straightforward. If the loss in precision of the latter is tolerable, then one does not need to write a conversion program since an assign command on the SGI will already do the job. File conversion is easy on the Cray, but there are many reasons why a user might prefer to do it on an Origin2000 instead. Users may simply want to avoid using their Cray time allocation to do file conversion, for example, or they may not know exactly which old files will be needed in the future.