Tandem Capacity Model (TCM) Manual

Figure 30 TCM Parameters Screen
CPU Tunability
The CPU Tunability field can be specified for each process category. It is used only for batch activity
and is ignored for OLTP activity. It indicates whether a process category runs in one or all available
batch CPUs. The default is N (no) for process categories that participate in batch transactions only.
N (no) indicates batch transactions are assigned to run in only one CPU. The default is Y (yes) for
process categories that participate in at least one OLTP transaction. Yes indicates that batch
transactions are spread evenly across all available batch CPUs.
TMF always defaults to nontunable because it is assumed that the major portion of its work is done
by one audit disk process.
In the Demo model included with TCM, the Tape Read and Cust Update categories are not tunable.
That is, they run in only one CPU. In contrast, the FastSort category is tunable. It runs in all CPUs
that are available to batch transactions.
The TCM administrator can modify this field on the Actual or Plan Baseline Detail by Category
screen.
You can modify the Tunable CPU field in the Plan Baseline Detail by Category screen. Figure 31
(page 103) shows a sample Plan Baseline Detail by Category screen.
102 Modeling Batch Workloads