If no vector-present CPU is available, OpenVMS executes vector
    instructions using the VAX Vector Instruction Emulator Facility
    (VVIEF), which is much slower than scalar execution.

                                   NOTE

       VVIEF must be enabled on the OpenVMS system; it is disabled
       by default. To enable VVIEF, the system manager must execute
       the command file SYS$UPDATE:VVIEF$INSTAL.COM. For more
       information, refer to your OpenVMS documentation set.