 Because 16 computers have 16 times as much memory as 1 (assuming all computers are identical), 16 computers with TDS can store more transpositions than 1 and therefore have to compute less.When the one computer gets 16 times as much memory as each of the group of 16, speedup is just below linear.Because the communication scheme in TDS uses only point-to-point communication and no broadcasting or other group communication, the amount of total communication is proportional to the number of computers participating the computation.