Question

Suppose a program takes 10000 seconds to run on single processor system. However, the parallel version of the program takes only 3200 seconds to run on a four processor (four core) system.

a) Find the speed up of the parallel program over the serial one.
b) The parallel program runs for a while in a serial mode and then in a parallel node. Find out the time the program spends in the serial mode of execution.

Answer 1

a. Speed up = 3.125

b. Time spent in serial mode = 6800 seconds

Step-by-step explanation:

a) The speed up of the parallel program can be found by dividing the time it takes to run on the serial system by the time it takes to run on the parallel system.

Speed up = Time to run on serial system / Time to run on parallel system

Speed up = 10000 seconds / 3200 seconds

Speed up = 3.125

b) To find the time the program spends in the serial mode of execution, we can subtract the time it takes to run on the parallel system from the total time it takes to run on the serial system.

Time spent in serial mode = Total time to run on serial system - Time to run on parallel system

Time spent in serial mode = 10000 seconds - 3200 seconds

Time spent in serial mode = 6800 seconds