System and user defaults system values: Processor multitasking

The Processor multitasking system value is also known as QPRCMLTTSK. You can use this system value to specify whether multitasking is on, off, or system controlled.

You can work with this system value from the character-based interface; it is not available in IBM® Navigator for i.

Quick reference
Location Character-based interface.
Special authority All object (*ALLOBJ) and security administrator (*SECADM).
Default value System controlled (2).
Changes take effect Immediately.
Lockable No.

What can I do with this system value?

You can control processor multitasking. This system value controls whether the hardware processes only one or more than one task at a time on a processor.

This system value has the following values:

Off (0)
Each processor supports the processing of only one task at any moment.
On (1)
Processors can concurrently process multiple tasks.
System controlled (2)
Processors can concurrently process multiple tasks. The system-controlled state also enables the operating system to occasionally limit a processor to processing one task at most.

The value that you specify should be based on performance and is workload dependent. By allowing multiple tasks per processor, the performance capacity of the system tends to increase. Therefore, the system processes more work. By limiting processors to run single tasks, the system tends to allow individual tasks to run faster.

Changes to the system value take effect immediately on Power6® and later hardware.

The shipped value is system controlled (2).