I've been coming across a problem in one of my assignments requiring the calculation of the speedup of a two-way superscalar cpu. The problem is as follows:
There is a two-way superscalar CPU with 2 pipelines U & V. The instruction pipeline U processes the complex instructions, while the instruction pipeline V processes the simple instructions. The ratio of the processing times in the phases of pipelines U and V is 3:1. I'm required to calculate the processing time for 1000 instructions in GPSS (General Purpose Simulation System) - Student Version, for the following cases:
50% complex and 50% simple instructions 25% complex and 75% simple instructions 75% complex and 25% simple instructions Probability of 50% complex and 50% simple instructions Probability of 25% complex and 75% simple instructions Probability of 75% complex and 25% simple instructions
I have the simulation files and i can deduce the execution time for each case T(Supuperscalar).
However I'm stuck with the requirement of finding the speedup for each case.
I'm aware that the speed up can be calculated as Speedup = T(Sequential)/T(superscalar) = k*n/k+(n-1) where k is the number of stages and n is instruction number, however I'm having a hard time figuring out how to calculate the sequential time for the above cases.
I would really appreciate if somebody can give me a hint here.