as400 V5R3 Memory Affinity Boosts Performance

Memory Affinity Boosts Performance
With the dramatic improvements in processor speed and processor optimizations, storage access latencies
continue to be a limiting factor in fully utilizing available processing power. Therefore it is important for
the Operating System (OS) to provide memory management support to fully optimize processor
utilization. IBM i5/OS™ V5R3 takes advantage of a characteristic of the POWER4 and POWER5
Symmetric Multiprocessor (SMP) topology to boost performance. This base OS facility called Memory
Affinity controls both how tasks are dispatched to processors and how storage is allocated on their
behalf. But further performance may also be available through the use of a provided set of work
management controls.
Using these controls where appropriate takes minimal effort, but it comes at a cost; you first need to
understand a few basics about cache and multiprocessor topology in POWER4 and POWER5 processors.