Polled Interrupt

An interrupt controller will poll all devices on a computer to determine which one sent out the request. Polled interrupt is an inefficient method of data transfer, spending much time checking the ready condition of a computer's devices.

An alternative that is more efficient is a vectored interrupt, which can send a signal that includes the identity of the device. All input/output in modern computers is done by interrupt-driven I/Os, which interrupt the process when they are ready to transfer data. The processor will perform other tasks while waiting for an interrupt.