The Savings Growth Rate, found in Plan Settings, it is used as the default interest rate (Growth Rate) for cash accounts, which are found on the Savings screen. This default interest rate is used provided that the "Use 100% Cash Asset Allocation" option is not selected for the account.
If the "Grow all savings and cash accounts using 100% Cash Asset Allocation" option is selected, an asset allocation of 100% Cash Allocation will be used to derive a growth rate from the software's market assumptions.
The default interest rate is taken from Plan Settings, but this default can be easily overridden for any account individually. To change the interest rate for a particular cash account, select the account and adjust the interest rate on the Basics screen.