VMS Help Sys Parameters, MC_SERVICES_P9  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    (Alpha only) MC_SERVICES_P9 specifies the number of initial
    entries in a single channel's free queue. The maximum value is
    2048, and the minimum value is 10.

    Note that MC_SERVICES_P9 is not a dynamic parameter; you must
    reboot the system after each change for that change to take
    effect.

    The default value is 150. Compaq recommends that this value not
    be changed.

    The value of MC_SERVICES_P9 must be the same on all nodes
    connected by MEMORY CHANNEL.