System information

Chapter 12. Using Work Management to influence System i5 resources 373
Figure 12-1 Processors and memory layout for n-way PowerPC MCMs
The memory affinity support recognizes the relationship between processors, memory, and
multichip modules (MCMs) in SMP machines such as the IBM ^ System i5. The
support provides improved performance to some high performance computing applications.
Memory affinity is a special purpose option for improving performance on IBM System i5
machines that contain multiple multichip modules. But memory affinity is neither
recommended nor beneficial for general use. Most systems run better with memory affinity
disabled. IBM testing has discovered that memory affinity can have an unpredictable effect on
system and application performance. Some applications benefit from memory affinity, others
can degrade.
12.2 Work Management enhancements for memory and
processor affinity
The following performance system values are new for i5/OS V5R3:
򐂰 QTHDRSCAFN — Thread affinity
򐂰 QTHDRSCADJ — Automatically adjust thread resources
The following parameters are new for the Add Routing Entry (ADDRTGE) command:
򐂰 THDRSCAFN — Thread resources affinity
򐂰 RSCAFNGRP — Resources affinity group