Using PAGE-AHEAD for large FORTRAN programs

Virtual storage management allows an efficient use of computer memory through the cooperative actions of the computer hardware and the operating system which are completely transparent to application programs. However, when program data exceed the available memory space, the program elapsed time may be dominated by the time spent in paging I/O operations. The data transfer rate, as determined by the operating system implementation of demand paging, may be small when compared with the maximum I/O bandwidth that the I/O hardware could support.