1. A method for performing a calculation of a data-based function model in a control unit, the method comprising: loading a first part of configuration data, which contain a first part of supporting point data having multiple supporting points, into a model calculation unit, wherein the control unit includes a computing unit and the model calculation unit, which is a separate model calculation unit having a computing core; starting a calculation in the computing core of the model calculation unit to obtain a model value at a predefined test point, wherein the calculation is started before the first part of the configuration data is completely loaded; transferring a second part of the configuration data, which contain a second part of the supporting point data having multiple supporting points, into the model calculation unit, prior to a completion of the calculation in the computing core of the model calculation unit; calculating in the computing unit at least one output variable with an aid of the calculation in the computing core of the model calculation unit; and operating an internal combustion engine based on the output variable by controlling at least one of an actuator and an injector of the internal combustion engine based on the output variable.