Suppose thread one is downloading a 800KB file while another thread is processing the same file on a multi-CPU machine.Suppose further that one time slice allows the first thread to download about 10KB and that the second thread can process 10KB of the file in one time slice.The second thread can process the file while it is incomplete.What is the minimum number of CPUs that will allow the job to be completed in roughly half the time of a single-CPU machine?
A)1
B)2
C)3
D)4

Question

Quizplus · Accepted Answer

If we have two CPUs, they can work concurrently on the same file. While one CPU is downloading the file, the other can process the downloaded part of the file. As the downloading and processing rate is the same, the processing thread will be able to keep up with the downloading thread. Therefore, the minimum number of CPUs required is 2. Having more CPUs may further decrease the processing time, but it is not necessary to complete the job in roughly half the time.

Suppose Thread One Is Downloading a 800KB File While Another