A portable computer system such as a laptop computer, for example, includes a first processor that may execute instructions corresponding to application software during a first mode of operation. The portable computer system also includes a second processor that may execute the instructions during a second mode of operation. The first processor and the second processor may be heterogeneous processors. Further, operation of the first processor and the second processor in the first mode and the second mode may be dependent upon which of a plurality of system preferences have been selected.