Defines the maximum number of page I/O requests that can be queued by the paging system. This number is divided by 4 to get the actual maximum number used by the paging system. This parameter is used to throttle the number of requests as well as to control process swapping.
1 to a variable maximum that depends on the system architecture, but mainly by the I/O subsystem, such as the number of controllers, disks, and disk swap size
The maximum number of I/O requests from the pager is limited by the size of a list of request buffers, which is currently sized at 256.
Increase this parameter to page out memory faster. A larger value might help to recover faster from memory pressure if more than one swap device is configured or if the swap device is a striped device. Note that the existing I/O subsystem should be able to handle the additional I/O load. Also, increased swap I/O could degrade application I/O performance if the swap partition and application files are on the same disk.
For information, see maxpgio (Solaris 10 Releases).