Appendix A. CPW and CIW Descriptions
"Due to road conditions and driving habits, your results may vary." "Every workload is different." These
are two hallmark statements of measuring performance in two very different industries. They are both
absolutely correct. For iSeries and AS/400 systems, IBM has provided a measure called CPW to represent
the relative computing power of these systems in a commercial environment. The type of caveats listed
above are always included because no prediction can be made that a specific workload will perform in the
same way that the workload used to generate CPW information performs.
Over time, IBM analysts have identified two sets of characteristics the appear to represent a large number
of environments on iSeries and AS/400 systems. Many applications tend to follow the same patterns as
CPW - which stands for
Commercial Processing Workload
. These applications tend to have many jobs
running brief transactions in an environment that is dominated by IBM system code performing database
operations. Other applications tend to follow the same patterns as CIW - which stands for
Compute
Intensive Workload
. These applications tend to have somewhat fewer jobs running transactions which
spend a substantial amount of time in the application, itself. The term "Compute Intensive" does not mean
that commercial processing is not done. It simply means that more CPU power is typically expended in
each transaction because more work is done at the application level instead of at the IBM licensed internal
code level.
A.1 Commercial Processing Workload - CPW
The CPW rating of a system is generated using measurements of a specific workload that is maintained
internally within the iSeries Systems Performance group. CPW is designed to evaluate a computer system
and associated software in the commercial environment. It is rigidly defined for function, performance
metrics, and price/performance metrics. It is NOT representative of any specific environment, but it is
generally applicable to the commercial computing environment.
y
What CPW is
Test of a range of data base applications, including simple and medium complexity updates,
simple and medium complexity inquiries, realistic user interfaces, and a combination of
interactive and batch activities.
Test of commitment control
Test of concurrent data access by large numbers of users running a single group of programs.
Reasonable approximation of a steady-state, data base oriented commercial application.
y
What CPW is not:
An indication of the performance capabilities of a system for any specific customer situation
A test of "ad-hoc" (query) data base performance
y
When to use CPW data
Approximate product positioning between different AS/400 models where the primary
application is expected to be oriented to traditional commercial business uses (order entry,
payroll, billing, etc.) using commitment control
IBM i 6.1 Performance Capabilities Reference - January/April/October 2008
©
Copyright IBM Corp. 2008
Appendix A - CPW and CIW Descriptions
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