Q2,paper 3,D 12.The efficiency (E) and speed up (sp) for Multiprocessor with p processors satisfies :

(A) E <=p and sp<=p

(B) E <=1 and sp<=p

(C) E <=p and sp<=1

(D) E <=1 and sp<=1

Answer(B).

Speedup.Can be achieved by executing independent subtasks in parallel Efficiency ,Along with an increase in speedup comes a decrease inEfficiency.It can be due to factors such as contention, communication, and software structure.

 Amdahl's law states that the overall speedup of applying the improvement will be:

Speed up=1/((1-p)+p/s)

Here p is % of processes subject to speed up.when S is the speed up in those processes.