Amdahl's law
A major benefit of systolic arrays is that all operand data and partial results are contained within (passing through) the processor array. There is no need to access external buses, main memory or internal caches during each operation as is the case with standard sequential machines. The sequential limits on parallel performance dictated by Amdahl's law also do not apply in the same way, because data dependencies are implicitly handled by the programmable node interconnect.