AutoCal gives the user the power to utilize multi core PC’s for carrying out multiple simulations simultaneously. Hereby an ensemble of simulations may be completed faster than the standard sequential method. Thus, the multi core functionality reduces the overall simulation time when doing scenario runs or optimisation runs.
The simultaneous simulations may be used with all the simulation options. In the case of Scenario runs or Sensitivity analysis all the parameter sets to be evaluated by the model are submitted for execution at the beginning of the simulations. When all parameter sets are evaluated, the AutoCal simulation is finished. In the case of Parameter optimisation only the Population Simplex Evolution algorithm can be applied for simultaneous execution. For each iteration step in the algorithm the population of parameter sets to be evaluated are submitted for execution. When all the parameter sets of the population are evaluated on the individual processes, the main job processes the results and determines a new population of parameter sets to be evaluated, which are then submitted to the job queue for execution. The AutoCal simulation is finished when one of the stopping criteria of the algorithm has been reached.
Number of processes available
Informs the user of the number of processors available
Number of simultaneous simulations
The user selected number of simultaneous simulations to be carried out
Use single thread engine
By default auto calibration will only use one core per individual simulation i.e. the individual runs in the ensemble will not distribute the load on multiple cores. The latter is only of importance if the engine being launched can utilize multiple processors.
Selecting the number of simultaneous simulations
The book keeping of which cores are used when is handled by the auto calibration tool. All that is required on the user side is to decide how many of the cores on the PC should be used. This number should be chosen based on
1. The number of cores available on the PC. There is no gain in launching more simultaneous simulations than the number of cores available on the PC. The interface informs the user of the cores available.
2. The number of simulations that the license grants you access to. This number may vary depending on the contents of your license file. If you are uncertain of the number of simulations you can carry out, the information may be retrieved through the license administration interface, The latter is located under your MIKE Powered by DHI installation short cut in the start menu. Look for the model in question and find the number in the Max User column.
The number should be selected as the smallest of the two numbers.