IIRC the Propeller is an eight thread barrel CPU with the same number of pipeline stages. So it "retires" just one instruction per cycle. All PIO state machines

IIRC the Propeller is an eight thread barrel CPU with the same number of pipeline stages. So it "retires" just one instruction per cycle. All PIO state machines can run every cycle so they should be considered very small CPU cores. You can think of them as channel I/O co-processors for a microcontroller instead of a mainframe.