# VHPT SIZE

**VHPT_SIZE** is a system parameter that defines the number of kilobytes to allocate for the virtual hash page table (VHPT) on each CPU in the system: o 0 indicates that no VHPT is allocated. o 1 indicates that OpenVMS is to choose a default size that is appropriate for your system configuration. If a VHPT is created, the smallest size is 32KB. The VHPT_SIZE must be a power of 2 KB in size. If the number specified is not a power of 2, OpenVMS chooses a VHPT size to use for your system that is close to the number specified. If insufficient memory is available during system startup, OpenVMS might choose a smaller size for the VHPT of each CPU. A summary of possible values for VHPT_SIZE is in the following table: Value Description 0 Do not create a VHPT on each CPU. 1 (default) OpenVMS chooses a VHPT of an appropriate size for each CPU. n Create a VHPT of nKB for each CPU, where n is a power of 2 that is 32 or greater. (The maximum value, however, is platform-dependent.) This parameter is available on Alpha and Integrity systems only.