VMS Help V73 Features, Programming Features, Large Page-File Sections (Alpha)  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Page-file sections are used to store temporary data in private
    or global (shared) sections of memory. In previous releases of
    OpenVMS Alpha, the maximum amount of data that could be backed up
    to page files was 32 GB per process (4 process page files, each 8
    GB) and 504 GB per system (63 page files, each 8 GB).

    With OpenVMS Alpha Version 7.3, the previous limits for page-file
    sections were extended significantly to take advantage of larger
    physical memory. Now images that use 64-bit addressing can map
    and access an amount of dynamic virtual memory that is larger
    than the amount of physical memory available on the system.

    With the new design, if a process requires additional page-
    file space, page files can be allocated dynamically. Space is
    no longer reserved in a distinct page file, and pages are no
    longer bound to an initially assigned page file. Instead, if
    modified pages must be written back, they are written to the best
    available page file.

    Each page or swap file can hold approximately 16 million pages
    (128 GB), and up to 254 page or swap files can be installed.
    Files larger than 128 GB are installed as multiple files.