In programmed IO, IO operations are programmed in the CPU. CPU will be waiting until IO operation is completed. Hence, CPU utilisation is very poor and the CPU time depends on the speed of the IO DEVICE and amount of data to be transferred.
Whereas, in Interrupt driven IO, IO operations are controlled by the IO Interface chip. Hence, processor utilisation is efficient. CPU time depends on the latency of the IO Interface Chip rather than speed of IO Device which is much slower than IO interface chip speed.