Question

A computer has a CPU that can execute 10 million instructions per second and a memory has a transfer rate of 100 million bytes per second. When interrupt-driven I/O is performed, the ISR has to execute 50 instructions to transfer one byte between memory and I/O device. What is the maximum data transfer rate during I/O operations implemented by using interrupt-driven I/O

Answer 1

Answer:

2 x 10⁵ bytes per second

Explanation:

Given:

MIPS rate = maximum speed of CPU to execute instructions = 10 million instructions per seconds

number of instructions required to transfer 1 byte using interrupt driven I/O = 50

Maximum number of bytes that can be transferred in 1 second = MIPS rate / number of instructions for 1 byte

=> max number of bytes = 10 million / 50 = 10 x 10⁶ / 50 = 2 x 10⁵

which is less than the maximum transfer rate of memory = 100 million bytes per second

So, maximum data transfer rate during I/O operations by using interrupt-driven I/O is 2 x 10⁵ bytes per second