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

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

    The vector scheduling subsystem presently provides an enlarged
    quantum to processes requiring vector capability. Customer sites
    can disable vector quantum adjustment by setting bit NO_VEC_
    QUANTADJ (bit 9) in the system parameter SCH_CTLFLAGS. Setting
    this bit causes the scheduler to treat the vector processes
    and scalar processes uniformly. However, doing so results in
    more frequent vector context switches when the number of vector
    processes exceeds the number of vector processors in the system.

    SCH_CTLFLAGS is a DYNAMIC parameter.