When a reseller or IBM Business Partner sizes a Power11 configuration, they are usually comparing benchmark ratings, not raw core counts. Knowing what these numbers mean helps you evaluate a proposed configuration instead of taking it on faith.
CPW for IBM i workloads
Commercial Processing Workload (CPW) is IBM's benchmark rating for comparing relative processing capacity on IBM i systems. A higher CPW rating generally indicates more processing capacity for typical IBM i commercial workloads. CPW is the standard reference point when comparing your current system's capacity against a proposed Power11 configuration.
rPerf for AIX and Linux workloads
Relative Performance (rPerf) plays a similar role to CPW but is used for AIX and Linux workload comparisons. If your Power11 evaluation spans IBM i, AIX, and Linux partitions on the same system, you may see both CPW and rPerf referenced for different partitions.
Why these numbers matter in a quote
Benchmark ratings are how a reseller translates your current workload into a target Power11 configuration. Bringing your own performance data (from IBM's Performance Management tools or Collection Services) into the conversation, rather than relying solely on published benchmark tables, produces a much more accurate sizing recommendation.
What benchmarks do not tell you
CPW and rPerf are useful for relative comparisons, but they do not capture application-specific behavior, I/O patterns, or peak batch windows. Use them as a starting point for sizing discussions, not as the final word on whether a configuration will meet your workload's real-world demands.