Operations are in parallel programmed


#1

If 25% of the operations in parallel program must be performed sequentially. What is the
maximum speedup achieved ?
A) 3 B) 4 C) 6 D) 8


#2

Option(B) is correct.

By Amdahl’s law,

Theoretical SpeedUp = 1/(1 - f + f/s)
where ‘f’ is the part or fraction getting benefited from speedup.
‘s’ is the speedup achieved by that part or fraction.

It is maximum when f/s tends to 0 i.e. s tends to infinity.

Max Speedup = 1/(1-f)
= 1/(1-0.75)

= 1(0.25)

= 4