VMS Help Sys Parameters, PIXSCAN  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    PIXSCAN specifies the number of process index slots scanned each
    second for computable or computable-outswapped processes. These
    processes receive an automatic priority boost for 1 quantum,
    unless the priority of the currently executing process is greater
    than 15. The priority boost is done to avoid potential deadlocks
    on the system.

    This special parameter is used by Compaq and is subject to
    change. Do not change this parameter unless Compaq recommends
    that you do so.

    PIXSCAN is an AUTOGEN and DYNAMIC parameter.