MPW_WRTCLUSTER

   MPW_WRTCLUSTER sets the number of pages to be written during one
   I/O operation from the modified-page list to the page file or
   a section file. The actual size of the cluster may be limited
   by the number of pages available for the I/O operation. This
   parameter can range in value from 16 to 120, in multiples of 8.
   Each page in the cluster requires 6 bytes of permanently resident
   memory.

   If MPW_WRTCLUSTER is too small, it takes many I/O operations
   to empty the modified-page list. If MPW_WRTCLUSTER is too large
   for the speed of the disk that holds the page file, other I/O
   operations are held up for the modified-page list write.

   On Alpha and Integrity servers, the MPW_WRTCLUSTER default value
   is 64 8192-byte pages; its maximum value is 512 8192-byte pages;
   and its minimum value is 16 8192-byte pages.

   MPW_WRTCLUSTER has the AUTOGEN and GEN attributes.