Abstract: A method for managing a calculation task on a functionally asymmetric multicore processor, at least one core of the processor associated with one or more hardware extensions, comprises the steps of receiving a calculation task associated with instructions that can be executed by a hardware extension; receiving calibration data associated with the hardware extension; and determining an opportunity cost of execution of the calculation task as a function of the calibration data. Developments describe the determination of the calibration data in particular by counting or by computation (on line and/or off line) of the classes of the instructions executed, the execution of a predefined set of instructions representative of the execution room of the extension, the inclusion of energy and temperature aspects, the translation or the emulation of instructions or the placement of calculation tasks on the different cores. System and software aspects are described.