While this information is interesting, it is often not directly relevant to the task of developing an efficient parallel program. Because it deals with large N and P , it ignores lower-order terms that may be significant for problem sizes and processor counts of practical interest. A second deficiency of asymptotic analysis is that it says nothing about absolute cost. N is superior to an algorithm with cost . For example, they may assume the PRAM model, in which communication costs are assumed to be nil.
Asymptotic analysis has a role to play in parallel program design.
However, when evaluating asymptotic results, we must be careful to identify the machine model for which the results are obtained, the coefficients that are likely to apply, and the N and P regime in which the analyses hold.