Question

how double buffering minimizes the idle time for devices and maximize their throughput

Answer 1

Double buffering means a device which have two buffers. One buffer is used for reading and another buffer is used for writing.

• For example, let us consider a disk is a storage device that have two buffers.Now computer monitor wants to display the data by accessing from the disk. So first disk writes the data to one buffer. This buffer transforms the data to other buffer. It means if disk writes the data to buffer1 and then buffer2 copies the data from buffer1. Now monitor reads the data in buffer 1. So while monitor reads the data from buffer1 , the next data which to be processed is filled in buffer 2.
• By this technique, user do not require to fill the data in buffer after reading the data which is not done simultaneously.

The below diagram shows how double buffer works :

In above diagram, shows that Monitor is accessing the data from buffer 2 , and at a same time buffer1 is filling with data which to be processed next in buffer2. The both operations are done at a time .

By this technique, user can reduce the work like filling the data in buffer to be processed on monitor, reading the data from the same buffer. In this technique, user is not required to fill the data in buffer. This makes the time consuming is less because reading and writing operations are done simultaneously. By this technique, it minimizes the idle time. And Maximum throughput is achieved because of fast data transferring from disk to monitor(as shown in diagram) by using two buffers (one is filling(Writing), one is for reading) which makes the execution faster.