RNI reflects the distribution and latency of sourcing data from shared caches and memory, as  shown in Figure 12-3. Many factors influence the performance of a workload. However, these factors often are  influencing is the RNI of the workload. The interaction of all these factors results in a net RNI  for the workload, which in turn directly relates to the performance of the workload. These factors are tendencies, not absolutes. For example, a workload might have a low I/O  rate, intensive processor use, and a high locality of reference, which all suggest a low RNI.  But, it might be competing with many other applications within the same LPAR and many  other LPARs on the processor, which tends to create a higher RNI. It is the net effect of the  interaction of all these factors that determines the RNI. The traditional factors that were used to categorize workloads in the past are shown with their  RNI tendency in Figure 12-4. L1 The “Nest” L2LP L4LP L2RP L4RP MEMP Microprocessor Design Memory Hierarchy or Nest How Often? L1MP How intensely this part of the  architecture is utilized L3P RNI How Far? Low Relative Nest Intensity High Batch  Application Type Transactional Low IO Rate High Single  Application Mix Many Intensive  CPU Usage Light Low  Dispatch Rate High High locality Data Reference Pattern Diverse Simple LPAR Configuration Complex Extensive Software Configuration Tuning Limited Figure 12-3 Relative Nest Intensity Figure 12-4 Traditional factors that were used to categorize workloads Little can be done to affect most of these factors. An application type is whatever is necessary  to do the job. The data reference pattern and processor usage tend to be inherent to the  nature of the application. The LPAR configuration and application mix are mostly a function of  what must be supported on a system. The I/O rate can be influenced somewhat through  buffer pool tuning. However, one factor,  software configuration tuning , is often overlooked but can have a direct  effect on RNI. This term refers to the number of address spaces (such as CICS  application-owning regions [AORs] or batch initiators) that are needed to support a workload.  402  IBM 14 Model ZR1 Technical Guide