A multi-threaded microprocessor (1105) for processing instructions in threads. The microprocessor (1105) includes first and second decode pipelines (1730.0, 1730.1), first and second execute pipelines (1740, 1750), and coupling circuitry (1916) operable in a first mode to couple first and second threads from the first and second decode pipelines (1730.0, 1730.1) to the first and second execute pipelines (1740, 1750) respectively, and the coupling circuitry (1916) operable in a second mode to couple the first thread to both the first and second execute pipelines (1740, 1750). Various processes of manufacture, articles of manufacture, processes and methods of operation, circuits, devices, and systems are disclosed.