Tandem Capacity Model (TCM) Manual

Figure 45 (page 141) shows a sample Consumption model.
Figure 45 Consumption Model
Significant Rows
1. Number—Constraint modifiable
Number is the actual, constrained, and planned number of CPUs and disks required to achieve
the performance specified by the constraints you set. The number of devices is for a well-tuned
system. If the system is not well-tuned, more CPUs, disks, or both could be required.
NOTE: TCM does not model disk space.
2. Processor Type and SW Release—Constraint modifiable
Processor type is the actual, constrained, and planned CPU types. SW Release is the NSK
release for the selected Processor Type. The user can select one of the values from the
drop-down lists that appear when these fields are clicked. Whenever the user selects a CPU
type, the value of the SW Release is automatically set to the latest NSK release for which this
CPU type is supported.
Valid CPU types and NSK releases are listed in the CPU Conversion Factors screen.
CPU seconds are scaled if the planned CPU type differs from the actual CPU type.
3. Disk Model—Constraint modifiable
Disk Model is the actual, constrained, and planned Disk Model number.
The user can select one of the values from the drop-down lists that appear when the Disk
Model field is clicked.
Valid Disk Model numbers are listed in the Disk Factors screen.
4. Disk Config—Constraint modifiable
Disk Config is the configuration type for all logical disk volumes in the sample. Valid Disk
configuration types are listed in the scratch areas of the TCM Parameters screen.
5. Disk Write Cache—Constraint Modifiable
Disk Write Cache is the actual, constrained, and planned Write Cache Configuration for the
selected Disk Model. Disk Write Cache specifies if the write cache enable (WCE) option is
ENABLED or DISABLED. For disks that support WCE, the default value is DISABLED. For disks
that do not support WCE, this field is NA (not applicable). Whenever the user selects a Disk
Consumption Model Screen 141