Every 4 milli-seconds an I/O device generates a 4000-byte block of data. This device is used with a computer whose processor runs at a clock rate of 3 GHz. The device can be configured to perform a DMA transfer of each 4000-byte data block and to generate an interrupt at the end of each DMA transfer. Setting up a DMA transfer on this system takes 500 cycles. Responding to each DMA interrupt and setting up the next transfer takes 2500 cycles.
As an alternative, the device can be configured to generate one byte of data at a time and generate an interrupt for each data byte. Processing the interrupt associated with each byte and copying the byte from the device into memory takes 2010 cycles.
A) After configuring the device, how many cycles per second would be consumed for I/O using interrupt driven DMA block transfers?
B) After configuring the device, how many cycles per second would be consumed for I/O if, instead, interrupts are used to transfer data one byte at a time from the device at the same rate as with the DMA approach?