An embodiment of a computing system is configured to process data using a multithreaded SIMD architecture that includes heterogeneous processing engines to execute a program. The program is constructed of various program instructions. A first type of the program instructions can only be executed by a first type of processing engine and a third type of program instructions can only be executed by a second type of processing engine. A second type of program instructions can be executed by the first and the second type of processing engines. An assignment unit may be configured to dynamically determine which of the two processing engines executes any program instructions of the second type in order to balance the workload between the heterogeneous processing engines.